GAS  CHEMISTS  HANDBOOK 

COMPILED  BY  TECHNICAL  COMMITTEE 
SUB-COMMITTEE  ON  CHEMICAL  TESTS 

1916 
C.  C.  TUTW1LER,  Chairman 


A.  P.  BEARDSLEY 
S.  R.  CHURCH 
W.  H.  FULWEILER 
R.  G.  GRISWOLD 
C.  E.  LEWARS 
J.  M.  MOREHEAD 
C.  J.  RAMSBURG 
E.  C.  UHLIG 
A.  B.  WAY 
ALFRED  H.  WHITE 


A.  F.  KUNBERGER,  Editor 


PUBLISHED  BY  THE  AMERICAN  GAS  INSTITUTE 
NEW'YORK  CITY 


\ 

ft^ 

CONTENTS 


CHAPTER  I. 

RAW  MATERIALS 
Coal 
Coke 
Gas  Oil 
Purification  Material 

CHAPTER  II. 

PRODUCTS -OF  GAS  MANUFACTURE 
Illuminating  Gas 
Ammonia 
Tar 
Cyanogen 

CHAPTER  III. 
IMPURITIES  IN  GAS 

Hydrogen  Sulphide 

Carbon  Bisulphide 

Ammonia 

Tar 

Naphthalene 

Cyanogen 


CHAPTER  IV. 
TAR  PRODUCTS 
"   JHbtler<0$     (Drip  Oil) 
" 


Tar  Oils 
Road  Tars 
Naphthalene  Salts 

CHAPTER  V. 

MISCELLANEOUS 

Construction  Materials 
Alloys 

Lubricating  Oils 
TABLES    * 


(The  Institute  is  not  responsible  for  statements  of  facts  or 

opinions  expressed  in  advance  papers.     This  paper  is 

subject  to  revision  by  the  Board  of  Directors.) 

(Copyright,  1916,  by  American  Gas  Institute.) 


REPORT  OF  COMMITTEE  ON  CHEMICAL  TESTS. 


WRITTEN  FOR  THE  ELEVENTH  ANNUAL,  MEETING  OF  THE  AMER- 
ICAN GAS  INSTITUTE,  OCTOBER,  1916,  BY  C.  C.  TUTWILER, 
CHAIRMAN. 


Since  the  last  meeting  of  the  Institute,  the  Committee  on 
Chemical  Tests  has  directed  its  activities  chiefly  toward  the 
revision  of  the  Gas  Chemists'  Handbook,  compiled  in  1914  by 
Mr.  W.  H.  Fulweiler. 

Mr.  Fulweiler,  in  presenting  his  report  at  the  Ninth  Annual 
Meeting  of  the  Institute,  stated  as  follows : 

The  magnitude  and  delicacy  of  this  work  is  fully  realized 
and  this  is  presented  primarily  as  a  progress  report.  In  time, 
the  Institute  would  be  well  repaid  for  the  expense  incurred  in 
the  publication  of  such  a  handbook  by  the  uniformity  of  practice 
that  would  result  from  the  adoption  of  these  methods  and  by  the 
convenience  to  the  gas  chemist  of  having  recognized  standard 
methods  pertaining  to  the  industry  collected  in  one  convenient 
publication. 

While  this  first  issue  of  the  Handbook  was  a  very  decided 
step  in  the  right  direction,  it  was  recognized  that  much  was 
still  to  be  accomplished  and  the  continuance  of  the  work  de- 
volved upon  the  1915  Committee  on  Chemical  Tests.  This 
Committee  was  unable  to  do  more  than  report  satisfactory 
progress  at  the  1915  meeting  of  the  Institute  and  the  same 
Committee  was  re-appointed  to  continue  the  revision  over 
1916. 

It  was  felt  from  the  start  that  it  was  of  first  importance  that 
the  work  should  be  carried  out  by  a  committee  whose  activi- 
ties covered  as  wide  a  field  as  possible,  not  only  in  the  gas 
industry  but  in  collaterial  lines  as  well,  especially  in  the  coke 
oven  and  coal  tar  by-product  industries  which  are  becoming 


452052 


yearly  more  closely  identified  with  the  gas  business.  For  this 
reason,  special  effort  was  made  to  enlist  the  co-operation  of 
chemists  skilled  in  these  various  lines  and  I  have  felt  myself 
and  the  Institute  most  fortunate  in  having  secured  the  assist- 
ance of  the  gentlemen  who  served  with  me  on  the  Committee 
in  1915  and  1916. 

Mr.  Fulweiler,  in  concluding  his  report,  states : 

It  is  urged  that  special  attention  be  given  to  the  question  of 
standard  methods  and  to  the  peculiar  conditions  under  which 
samples  must  be  taken  in  the  gas  industry. 

The  Committee  has  felt  with  Mr.  Fulweiler  that  the  stand- 
ardization of  methods  of  testing  and  sampling  was  the  chief 
consideration  to  which  it  should  devote  its  attention,  and  in 
the  Handbook  which  we  now  offer  for  your  consideration,  we 
have  endeavored  to  round  out  as  far  as  possible  the  work  of 
the  first  committee  and  to  standardize  and  bring  up-to-date 
methods  which  have  been  developed  or  improved  since  the 
work  was  inaugurated  in  1914.  It  is  hoped  that  owing  to 
the  wide  connections  of  the  members  of  the  Committee  and 
the  various  sources  from  which  these  methods  have  been 
drawn  that  progress  has  been  made  toward  the  accomplish- 
ment of  this  much  desired  result. 

The  Committee  has  devoted  a  considerable  amount  of  time 
to  the  consideration  of  proper  methods  of  sampling,  recog- 
nizing the  fact  that  unless  the  sample  is  properly  taken,  the 
analysis  might  not  only  be  worthless,  but  absolutely  mislead- 
ing. We  have  endeavored  to  have  the  directions  for  sampling 
as  well  as  for  testing  so  clear  that  little  difficulty  will  be  en- 
countered even  by  chemists  of  limited  experience. 

The  Committee,  recognizing  the  great  progress  being  made 
in  the  application  of  chemistry  to  the  gas  industry  and  feeling 
that  even  companies  of  moderate  size  can  well  afford  to  have 
on  their  staff  chemists  or  men  of  some  chemical  training,  has 
kept  in  mind  primarily  the  assistance  of  these  men  rather  than 
the  engineer,  although  it  has  endeavored  to  present  the  subject 
matter  in  a  manner  which  may  be  easily  understood  by  all. 
It  will  be  noted  that  no  attempts  have  been  made  to  interpret 


the  results  of  the  analyses,  nor  have  theoretical  considerations 
been  touched  upon  to  any  great  extent,  it  being  felt  that  this 
phase  of  the  subject  might  better  be  left  to  succeeding  com- 
mittees, possibly  to  be  covered  in  a  separate  publication. 

We  have  included  in  the  Handbook  such  of  the  most  useful 
tables  of  constants  and  data  as  are  most  frequently  required. 
But  in  view  of  the  fact  that  there  are  now  so  many  reference 
books  readily  available,  matter  of  this  kind  has  been  kept  to  a 
minimum. 

While  the  Committee  feels  that  distinct  progress  has  been 
made  in  the  Handbook,  it  is  not  prepared  to  recommend  that 
all  of  the  methods  contained  therein  be  stamped  with  the 
official  approval  of  the  Institute  without  further  revision  by 
succeeding  chemical  test  committees  or  by  a  special  com- 
mittee appointed  for  the  purpose,  except  possibly  the  methods 
covering  the  analyses  of  coal  and  coke,  cement,  and  iron  and 
steel.  All  of  these  may  safely  be  adopted,  it  is  thought,  since 
the  method  for  analyses  of  coal  and  coke  is  based  on  the  work 
of  the  Bureau  of  Mines  and  those  for  cement,  iron  and  steel 
are  the  official  methods  of  the  American  Society  for  Testing 
Materials.  The  desirability,  however,  of  having  the  whole 
work  officially  approved  by  the  Institute  seems  apparent  and 
since  its  value  would  be  so  much  increased  by  such  action  of 
the  Institute,  the  Committee  feels  that  no  unnecessary  time 
should  be  lost  in  taking  the  necessary  steps  to  further  stand- 
ardize and  enlarge  the  work. 

In  conclusion,  I  wish  to  express  to  the  various  members  of 
the  Committee,  my  appreciation  of  their  efforts  in  behalf  of 
the  success  of  the  Handbook  and  especially  of  the  efforts  of 
those  gentlemen  not  directly  engaged  in  the  gas  business,  who 
have  given  their  assistance.  It  seems  proper  in  this  connection 
to  make  special  mention  of  the  work  of  Mr.  S.  R.  Church, 
Manager,  Research  Department,  The  Barrett  Company. 

I  also  wish  to  express  my  appreciation  of  the  efforts  of 
Mr.  A.  F.  Kunberger,  who  was  appointed  editor  of  the  Hand- 
book since  the  last  meeting  of  the  Institute  and  upon  whose 
shoulders  has  devolved  most  of  the  work  in  connection  with 


2d 

getting  into  suitable  form  for  publication  the. data  secured  by 
the  Committee. 

C.  C.  TUTWILER,  Chairman, 

A.  P.  BEARDSI,EY, 
1  S.  R.  CHURCH, 

W.  H.  FUIAVEH,KR, 

R.  G.  GRISWOLD, 

J.   M.   MOREHEAD, 

E.  C.  UHWG, 
C.  R.  RAMSBURG, 
A.  B.  WAY, 
A.  H.  WHITS. 


(The  Institute  is  not  responsible  for  statements  of  facts  or 

opinions  expressed  in  advance  papers.     This  paper  is 

subject  to  revision  by  the  Board  of  Directors.) 

(Copyright,  1916,  by  American  Gas  Institute.)' 


GAS  CHEMISTS'  HANDBOOK. 


CHAPTER  I. 

COAL  AND  COKE. 

The  following  determinations  are  covered  in  the  analysis  of 
coal  and  coke : 

Air-Drying  Loss. 

Moisture. 

Volatile  Matter. 

Fixed  Carbon. 

Ash. 

Sulphur. 

Phosphorus. 

Calorific  Value. 

Carbon. 

Hydrogen. 

Nitrogen. 

Oxygen. 

Shatter  Test  for  Coke. 

Apparent  and  Real  Specific  Gravity. 

These  determinations  are  based  on  reports  of  Committee 
"E~4"  of  the  American  Society  for  Testing  Materials,  on  Tech- 
nical Papers  No.  8  and  No.  76  of  the  Bureau  of  Mines. 


COAI,  SAMPLING 

The  coal  should  be  sampled  at  the  time  it  is  being  unloaded 
from  railroad  cars  or  other  means  of  transportation. 

To  collect  samples,  a  shovel  or  specially  designed  tool  or 
mechanical  means  should  be  used  for  taking  increments  of  10 
to  30  pounds  of  coal.  The  size  of  the  increments  must  depend 
on  the  size  and  weight  of  the  largest  pieces  of  coal  and  im- 
purities. 

The  increments  must  be  regularly  and  systematically  col- 
lected, so  that  the  entire  delivery  will  be  represented  propor- 
tionately in  the  gross  sample.  The  frequency  of  collecting  the 
increments  should  be  regulated  so  that  a  gross  sample  of  not 
less  than  1,000  pounds  will  be  collected. 

If  the  coal  contains  an  unusual  amount  of  impurities,  such 
as  slate,  and  if  the  pieces  of  such  impurities  are  very  large,  a 
gross  sample  of  more  than  1,000  pounds  should  be  collected. 

A  gross  sample  of  the  above  specified  quantity  should  be 
taken  for  delivery  of  500  tons  or  less.  When  deliveries  are 
made  in  large  quantities  as  in  cargoes  of  from  2,000  to  12,000 
tons,  the  size  of  the  gross  sample  must  be  governed  by  the  size 
and  amount  of  the  free  impurities.  A  gross  sample  of  from 
2,000  to  4,000  pounds  is  sufficient  for  reasonable  accuracy  un- 
less the  size  and  amount  of  the  free  impurities  are  unusually 
large. 

After  the  gross  sample  has  been  collected  it  must  be  system- 
atically crushed,  mixed  and  reduced  in  quantity  to  convenient 
size  for  transmittal  to  the  laboratory.  The  crushing  should  be 
done  by  a  mechanical  crusher  or  by  hand  with  a  tamper  or 
hammer  on  a  smooth  and  solid  floor.  In  the  absence  of  a 
smooth,  tight  floor,  the  crushing  may  be  done  on  a  heavy 
canvas,  to  prevent  the  accidental  admixture  of  any  foreign 
matter.  The  mixing  and  reduction  should  be  done  by  hand, 
with  a  shovel,  or  mechanically,  by  means  of  riffles  or  sampling 
machines. 

The  sizes  to  which  the  coal  and  impurities  should  be  crushed 
are  approximately  as  here  given. 


Size  to  which  pieces 

Weight  of  sample  should  be  broken 

to  be  divided  before  each  division 

1,000  pounds  or  more I  inch 

500  pounds  y±  inch 

250  pounds  y-2  inch 

125  pounds  y%  inch 

60  pounds  y^  inch 

If  the  sample  is  prepared  by  hand,  the  mixing  and  reducing 
should  be  done  by  the  "long  pile  and  alternate  shovel"  method 
on  amounts  of  125  pounds  or  more,  the  procedure  being  as 
follows : 

The  crushed  coal  is  shoveled  into  a  conical  pile.  A  long 
pile  is  formed  by  taking  a  shovelful  at  a  time  and  spreading 
it  out  in  a  straight  line  (8  to  10  feet  long  for  a  shovel  holding 
about  15  pounds).  Each  new  shovelful  is  spread  over  the  top 
of  the  preceding  one,  beginning  at  opposite  ends,  the  pile  being 
occasionally  flattened  with  the  flat  side  of  the  shovel  and  so  on 
until  all  the  coal  has  been  formed  into  one  long  pile. 

By  walking  around  the  long  pile,  advancing  a  distance  equal 
to  the  width  of  the  shovel,  and  systematically  taking  shovel- 
fuls, and  shoveling  the  coal  to  one  side,  alternate  shovelfuls 
being  discarded,  the  sample  will  be  halved  in  quantity. 

Whenever  the  different  increments  of  sample  are  collected 
throughout  some  considerable  period  of  time,  each  increment 
or  an  accumulation  of  a  number  of  increments,  may  be  crushed 
as  soon  as  taken  and  the  pieces  of  coal  and  impurities  broken 
sufficiently  small  to  permit  two  or  more  reductions  of  total 
accumulated  sample  before  further  crushing  is  necessary. 

If  the  sampling  should  extend  over  any  considerable  period, 
wrhat  would  otherwise  be  a  gross  sample  may  be  wrorked  down 
in  successive  stages  to  samples  of  a  size  suitable  for  transmittal 
to  the  laboratory,  and  these  samples  which  should  be  approxi- 
mately equal  in  quantity  and  as  representing  the  several  equal 
parts  of  a  delivery  may  be  analyzed  and  the  several  analyses 
averaged. 

Preparation  of  Laboratory  Samples. 
''The  quantity  of  sample  sent  to  the  chemist  will  be  governed 


by  the  relative  proportion  of  free  impurities  and  the  practical 
limits  of  fineness  to  which  these  impurities  can  be  crushed  at 
the  point  of  sampling.  Ordinarily  5  pounds  crushed  to  pass  a 
4-mesh  screen  is  a  convenient  sample  to  send  to  the  labora- 
tory." In  cases  where  it  is  not  feasible  to  crush  to  4  mesh 
at  the  point  of  sampling,  the  weight  of  the  sample  sent  to  the 
laboratory  must  conform  to  the  following  table : 

Size  of  largest  Minimum  weight 

impurities  of  sample 

In.  i,b. 

V2  75 

3/8  30 

V*  9 

3/16  or  smaller 5 

Samples  of  125  pounds  and  less  may  be  reduced  to  the  5- 
pound  quantity  by  a  riffle  sampler  or  on  a  canvas  as  follows : 
The  sample  is  placed  on  a  canvas  about  8  feet  square  and 
mixed  by  raising  first  one  end  of  the  canvas  and  then  the  other, 
thereby  rolling  the  sample  back  and  forth.  After  thoroughly 
mixing  in  this  manner,  by  gathering  up  the  four  corners  of 
the  canvas,  the  sample  will  be  formed  into  a  conical  pile  and 
is  to  be  reduced  in  quantity  by  quartering.  The  cone  is  flat- 
tened, its  apex  being  pressed  down  with  the  flat  side  of  the 
shovel,  or  with  a  board,  so  that  each  quarter  contains  the  ma- 
terial originally  in  it.  The  flattened  mass  which  should  be  of 
uniform  thickness  and  diameter  is  then  marked  off  into  quar- 
ters with  the  board  held  edgewise  or  with  a  piece  of  sheet  iron, 
along  two  lines  that  intersect  at  right  angles  directly  under  the 
apex  of  the  original  cone.  The  diagonally  opposite  quarters 
are  shoveled  away  and  discarded  and  the  space  which  they 
occupied  brushed  clean.  The  coal  remaining  is  successively 
mixed,  coned  and  quartered  on  the  canvas  until  two  opposite 
quarters  are  equal  to  the  quantity  required  to  fill  two  contain- 
ers holding  about  5  pounds  each.  The  coal  should  be  well 
packed  in  the  containers  so  as  to  exclude  air  as  much  as  possi- 
ble. 

Special  Moisture  Sample. 

In  the  reduction  of  the  gross  sample  to  the  sample  for  trans- 


mittal  to  the  laboratory,  there  will  be  an  unavoidable  loss  of 
moisture. 

To  determine  the  moisture  content  in  the  coal,  a  separate 
special  moisture  sample  must  be  taken. 

This  special  moisture  sample  should  contain  approximately 
100  pounds  and  should  be  accumulated  by  placing  in  a  water- 
proof receptacle,  with  a  tight  fitting  and  waterproof  cover, 
small  parts  of  the  freshly  taken  increments  of  the  gross  sample. 
These  parts  should  be  broken  to  about  ^2  inch  in  size  as 
accumulated. 

The  accumulated  moisture  sample  must  be  reduced  mechan- 
ically or  by  hand  as  quickly  as  possible  and  immediately  placed 
in  a  container  and  sealed  air-tight. 

Sampling  from  Loaded  Cars. 

If  it  becomes  necessary  to  sample  coal  from  a  loaded  car, 
the  sample  should  be  accumulated  by  digging  ten  or  fifteen 
holes,  two  or  three  feet  deep,  at  systematically  located  points 
over  the  car. 

Sampling  from  a  Storage  Pile. 

In  sampling  from  a  pile,  first  estimate  the  approximate  sur- 
face of  the  pile  and  then  determine  the  relative  distance  be- 
tween points  for  taking  increments,  sufficient  in  number  to 
insure  the  accumulation  of  the  requisite  amount  of  gross 
sample. 

Starting  at  three  or  four  feet  from  the  bottom  of  the  pile, 
take  shovelfuls  at  the  predetermined  distance  apart  around  or 
along  the  pile  on  the  same  level.  Then  begin  at  a  certain 
distance  up  the  pile  and  circle  it  again  so  on  to  the  top. 

Systematically  alternate  the  depth  of  the  holes,  taking  one 
shovelful  at  the  surface,  the  next  one  deeper,  the  next  still 
deeper,  the  fourth  at  the  surface  again  and  so  on. 

Sampling  at  the  Mines. 

The  sample  should  be  systematically  accumulated  through- 
out at  least  one  entire  day's  loading.  The  total  weight  of 


8 


sample  taken  should  be  governed  by  the  size  and  amount  of 
impurities  contained  in  the  coal. 

Samples  should  not  be  taken  from  the  tops  of  loaded  mine 
cars  as  they  are  likely  to  be  trimmed  with  lumps  and  also 
because  pieces  of  roof  or  draw  slate  may  have  fallen  onto  the 
car. 

Samples  of  the  coal  being  shipped  should  be  taken  while  the 
railroad  cars  are  being  loaded.  If  any  attempt  is  being  made 
to  throw  out  impurities  wThile  loading,  shovelfuls  should  be 
taken  from  the  slanting  surface  just  before  a  new  mine  car 
is  dumped  and  after  the  pickers  have  finished  cleaning  the  one 
previously  dumped.  The  shovel  should  be  pushed  well  into 
the  coal  to  avoid  getting  only  that  on  the  surface  from  which 
impurities  have  been  picked,  and  the  shovelfuls  should  be  taken 
systematically  from  various  parts  of  the  surface. 

SAMPLING  COKE. 

The  amount  of  gross  sample  of  coke  that  should  be  accumu- 
lated depends  on  the  size  of  the  coal  and  the  size  and  amount 
of  impurities  in  the  coal  from  which  the  coke  is  made. 

In  general  coke  is  made  from  slack  or  crushed  coal  and  in 
the  crushing  and  handling  of  the  coal  preparatory  to  charging 
it  into  the  ovens,  it  becomes  so  well  mixed  that  errors  due 
to  variations  in  its  quality  are  minimized. 

A  ioo-pound  sample  of  coke  is  usually  sufficient,  to  obtain 
accuracy  for  a  single  car,  but  where  larger  lots  are  to  be 
sampled  especially  when  the  entire  output  of  a  plant  is  to  be 
sampled,  four  or  five  separate  samples  of  50  pounds  or  more 
should  be  taken  and  the  results  averaged. 

Physical  appearance  as  regards  color  and  porosity  is  no  in- 
dication of  the  chemical  analysis. 

In  general,  the  moisture  content  increases  as  the  size  of  the 
pieces  of  coke  diminishes  and  to  some  extent  this  graduation 
is  true  in  the  ash  content  as  well.  It  is  necessary,  therefore, 
especially  in  sampling  run  of  oven  coke  that  due  care  should 
be  exercised  to  obtain  the  proper  proportions  of  lump  and 
fines.  A  great  many  small  pieces  from  many  different  parts  of 


the  lot  should  be  taken  by  breaking  off  long  slender  fingers 
from  the  lumps,  and  there  should  also  be  included  pieces  of 
all  sizes  and  shapes. 

A  special  moisture  sample  should  be  taken  as  in  the  case  of 
coal,  except  that  the  time  should  not  be  spent  in  crushing  finer 
than  i  inch  for  the  reason  that  in  the  crushing  and  mixing  of 
coke,  the  moisture  loss  is  much  more  rapid  than  with  coal. 

Preparation  of  Laboratory  Sample. 
APPARATUS. 

Air-Drying  Oven. — The  oven  is  to  be  used  for  air-drying 
wet  samples.  It  is  not  necessary  but  is  economical  where  many 
wet  samples  are  received.1  - 

Galvanised  Iron  Pans  18  x  18  x  1^2  Inches  Deep. — For  air- 
drying  wet  samples. 

Balance  on  Solution  Scale. — For  weighing  the  galvanized 
pans  with  samples.  It  should  have  a  capacity  of  5  kilograms 
and  be  sensitive  to  0.5  kilogram. 

Chipmunk  Jaw  Crusher. — For  crushing  coarse  samples  to 
pass  a  4-mesh  sieve. 

Roll  Crusher  or  Coffee  Mill  Type  of  Grinder. — For  reducing 
the  4-mesh  product  to  2o-mesh.  The  coffee-mill  type  of 
grinder  should  be  entirely  enclosed  and  have  an  enclosed 
hopper  and  a  receptacle  capable  of  holding  5  pounds  of  coal. 
This  is  to  reduce  the  moisture  losses  while  crushing. 
Abbe  Ball  Mill,  Planetary  Disk  Crusher,  Chrome  Steel  Buck- 
ing Board,  or  any  Satisfactory  Form  of  Pulverizer. — For  re- 
ducing the  2O-mesh  product  to  6o-mesh.  The  porcelain  jars 
for  the  ball  mill  should  be  approximately  9  inches  in  diameter 
and  10  inches  high.  The  flint  pebbles  should  be  smooth,  hard 
and  well  rounded.  "The  reduction  in  size  of  coke  for  the 
laboratory  should  not  be  done  by  grinding  in  an  apparatus 
which  will  give  up  fine  particles  of  iron  to  the  sample.  A 

1  For  details  of  air-drying  oven,  see  Bownocker,  lyord  and  Somermeier,  "Coal" 
Bulletin  No.  9,  4th  series,  Ohio  Geological  Survey,  P.  312  (1908);  or  F.  M.  Stanton 
and  A.  C.  Fieldner,  "Methods  of  Analyzing  Coal  and  Coke,"  Technical  Paper  No.  8, 
Bureau  of  Mines,  P.  4  (1912);  or  E.  E).  Somermeier,  "Coal,  Its  Composition,  Analysis, 
Utilization  and  Valuation,"  P.  71,  McGraw-Hill  Book  Co.,  (1912). 


10 

jaw  crusher  which  will  reduce  to  8-mesh  and  an  Abbe  Ball 
Mill  for  further  reduction  is  recommended." 

A  Large  Riffle  Sampler  with  y*  or  y%  inch  Divisions.— For 
reducing  the  4-mesh  sample  to  5  pounds.2 

A  Small  Riffle  Sampler  with  y^.  or  y%  inch  Divisions. — For 
dividing  down  the  20  and  6o-mesh  material  to  a  laboratory 
sample. 

An  8  inch  6o-mesh  Sieve  with  Cover  and  Receiver. 

Containers  for  Shipment  to  Laboratory. — A  galvanized  iron 
or  tin  can  with  a  screw  top,  which  is  sealed  with  a  rubber  gas- 
ket and  adhesive  tape  is  best  adapted  to  this  purpose.  Glass 
fruit  jars, sealed  with  rubber  gaskets  may  be  used  if  packed 
carefully  to  avoid  breakage  in  transit. 

Upon  receipt  of  the  sample  at  the  laboratory,  it  is  to  be  pre- 
pared for  analysis  by  one  of  two  methods,  as  follows : 

(A)    WHEN  COAI,  APPEARS  DRY. 

If  the  sample  is  coarser  than  4-mesh  (0.20  inch)  and  larger 
in  amount  than  10  pounds,  quickly  crush  it  with  the  jaw 
crusher  to  pass  a  4-mesh  sieve  and  reduce  it  on  the  larger  riffle 
sampler  to  10  pounds,  or  to  5  pounds  if  it  is  crushed  to  pass  a 
6-mesh  sieve;  then  crush  it  at  once  to  2O-mesh  by  passing 
through  rolls  or  an  enclosed  grinder,  and  take,  without  sieving, 
a  60  gram  total  moisture  sample,  immediately  after  the  ma- 
terial has  passed  through  the  crushing  apparatus.  This  sample 
should  be  taken  with  a  spoon  from  various  parts  of  the  20- 
mesh  product,  and  should  be  placed  directly  in  a  rubber- 
stoppered  bottle. 

Thoroughly  mix  the  main  portion  of  the  sample,  reduce  on 
the  small  riffle  sampler  to  about  120  grams  and  pulverize  to 
6o-mesh  by  any  suitable  apparatus  without  regard  to  loss  of 
moisture. 

After  all  the  material  has  been  passed  through  the  6o-mesh 
sieve,  mix  and  divide  it  on  the  small  riffle  sampler  to  60  grams. 
Transfer  the  final  sample  to  a  4-ounce  rubber-stoppered  bottle. 

-  For  details  of  riffle  sampler  see  Bulletin  No.  9,  4th  Series,  Ohio  Geological 
Survey,  P.  313  (1908),  or  15.  K.  Somermeier,  "Coal,  Its  Composition,  Analysis,  Utiliza- 
tion and  Valuation,"  P.  73,  McGraw-Hill  Book  Co.,  (1912). 


II 


Determine  moisture  in  both  the  60  and  the  2O-mesh  samples 
by  the  method  given  under  moisture. 

Computation. — Compute  the  analysis  of  the  6o-mesh  coal, 
which  has  become  partly  air-dried  during  sampling,  to  the  dry 
coal  basis,  by  dividing  each  result  by  I  minus  its  content  of 
moisture.  Compute  the  analysis  of  coal  "as  received"  from 
the  dry  coal  analyses  by  multiplying  by  I  minus  the  total 
moisture  found  in  the  2O-mesh  sample. 

(B)  WHEN  COAI,  APPEARS  WET. 

Spread  the  sample  on  tared  pans,  weigh,  and  air-dry  at  room 
temperature,  or  in  a  special  drying  oven,  at  10  to  15°  C.  above 
room  temperature,  and  weigh  again.  The  drying  should  be 
continued  until  the  loss  in  weight  is  not  more  than  o.i  per  cent, 
per  hour.  Complete  the  sampling  as  under  dry  coal. 

Computation. — Correct  the  moisture  in  the  2o-mesh,  air- 
dried  sample  to  total  moisture  "as  received"  as  follows : 

TOO— percentage  of  air-drying  loss  r 

—  X  percentage  of  moist- 
100 

ure  in  2o-mesh  coal  -f-  percentage  of   air-drying  loss  =  total 
moisture  "as  received." 

Compute  the  analysis  to  "dry  coal"  and  "as  received"  bases 
as  under  dry  coal,  using  for  the  "as  received"  computation  the 
total  moisture  as  found  by  the  formula  in  place  of  the  moisture 
found  in  the  2O-mesh  coal. 

Notes. — Freshly  mined  or  wet  coal  loses  moisture  rapidly  on 
exposure  to  the  air  of  the  laboratory,  hence  the  sampling  oper- 
ations between  opening  the  container  and  taking  the  2O-mesh 
total  moisture  sample  must  be  conducted  with  the  utmost  dis- 
patch and  with  minimum  exposure  to  air. 

The  accuracy  of  the  method  of  preparing  laboratory  samples 
should  be  checked  frequently  by  resampling  the  rejected  por- 
tions and  preparing  a  duplicate  sample.  The  ash  in  the  two 
samples  should  not  differ  more  than  the  following  limits : 

No  carbonates  present   0.4  per  cent. 

Considerable  carbonate  and  pyrite  present. . .  0.7  per  cent. 
Coals  with  more  than  12  per  cent,  ash,  con- 
taining considerable  carbonate  and  pyrite  i.o  per  cent. 


12 

Determination  of  Moisture.3 
APPARATUS. 

Moisture  Oven. — This  must  be  so  constructed  as  to  have  a 
uniform  temperature  in  all  parts  and  a  minimum  of  air  space. 
It  may  be  of  the  form  shown  here.  Technical  Paper  No.  j6, 
Bureau  of  Mines. 


FIG.  i. 

Provision  must  be  made  for  renewing  the  air  in  the  oven 
at  the  rate  of  two  to  four  times  a  minute,  with  the  air  dried 
by  passing  it  through  concentrated  sulphuric  acid. 

3  This  method  can  not  be  applied  to  lignites  which  have  to  be  dried  at  a  much 
higher  temperature. 


13 

Capsules  with  Covers. — A  convenient  form,  which  allows 
the  ash  determination  to  be  made  on  the  same  sample,  is  the 
Royal  Meissen  Porcelain  capsule  No.  2,  %  inch  deep  and  i% 
inches  in  diameter ;  or  a  fused  silica  capsule  of  similar  shape. 
Ihis  is  to  be  used  with  a  well-fitting  flat  aluminum  cover. 
Glass  capsules  with  ground  glass  caps  may  also  be  used.  They 
should  be  as  shallow  as  possible,  consistent  with  convenient 
handling. 

METHOD. 
(A)     SIXTY-MESH  SAMPLE. 

Heat  the  empty  capsules  under  the  conditions  at  which  the 
coal  is  to  be  dried.  Stopper  and  cover,  cool  over  concentrated 
sulphuric  acid,  specific  gravity  184,  for  30  minutes  and  weigh. 

Dip  out  with  a  spoon  or  spatula  from  the  sample  bottle  ap- 
proximately I  gram  of  coal;  put  this  quickly  into  the  capsule, 
close  and  weigh  at  once. 

An  alternate  procedure  (more  open  to  error)  after  trans- 
ferring an  amount  slightly  in  excess  of  I  gram  is  to  bring  to 
exactly  I  gram  in  weight  (0.5  milligram)  by  quickly  removing 
the  excess  weight  of  coal  with  a  spatula.  The  utmost  dispatch 
must  be  used  in  order  to  minimize  the  exposure  of  the  coal 
until  the  weight  is  found. 

After  removing  the  covers,  quickly  place  the  capsules  in  a 
pre-heated  oven  (at  104  to  110°  C.)  through  which  passes  a 
current  of  air  dried  by  concentrated  sulphuric  acid.  Close 
the  oven  at  once  and  heat  for  I  hour.  Then  open  the  oven, 
cover  the  capsules  quickly  and  place  them  in  a  desiccator  over 
concentrated  sulphuric  acid.  When  cool,  weigh. 

(B)    TWENTY-MESH  SAMPLE. 

Use  5  gram  samples,  weigh  with  an  accuracy  of  2  milli- 
grams, and  heat  for  il/>  hours;  the  procedure  is  otherwise  as 
with  the  6o-mesh  sample.  Methods  of  greater  accuracy  may 
be  found  in  the  "Proceedings  of  the  American  Society  for 
Testing  Materials,"  Vol.  XIV,  1914,  p.  421. 

The  allowable  variations  are  as  follows : 


14 

Same  analyst  Different  analyst 

per  cent.  per  cent. 

Moisture  under  5  per  cent. 0.2  0.3 

Moisture  over  5  per  cent. 0.3  0.5 

Determination  of  Volatile  Matter. 
APPARATUS. 

Platinum  Crucible  with  Tightly  Pitting  Cover. — The  crucible 
should  be  of  not  less  than  10  nor  more  than  20  cubic  centi- 
meters capacity:  of  not  less  than  25  nor  more  than  35  milli- 
meters in  diameter ;  of  not  less  than  30  nor  more  than  35  milli- 
meters in  height. 

Vertical  Electric  Tube  Furnace;  or  a  Gas  or  Electrically 
Heated  Muffle  Furnace. — The  furnace  may  be  of  the  form  as 
shown  here  (p.  21,  Technical  Paper  No.  76,  Bureau  of  Mines). 

It  is  to  be  regulated  to  maintain  a  temperature  of  950°  C. 
(-J-2O0  C.)  in  the  crucible,  as  shown  by  a  thermo-couple  in 
the  furnace. 

METHOD. 

Weigh  I  gram  of  the  coal  in  a  weighed  10  to  20  cubic  centi- 
meter platinum  crucible,  close  with  a  capsule  cover,  and  place 
on  platinum  or  nichrome-wire  supports  in  the  furnace  chamber, 
which  must  be  at  a  temperature  of  950°  C.  (+  20°  C.).  After 
the  more  rapid  discharge  of  volatile  matter  has  subsided,  as 
shown  by  the  disappearance  of  the  luminous  flame,  tap  the 
cover  lightly  to  more  perfectly  seal  the  crucible  and  thus  guard 
against  the  admission  of  air.  After  heating  exactly  7  minutes, 
remove  the  crucible  from  the  furnace  and,  without  disturbing 
the  cover,  allow  to  cool.  Weigh  as  soon  as  cold.  The  loss 
of  weight  minus  moisture  equals  volatile  matter. 

ALTERNATE  METHOD. 

One  gram  of  coal  is  placed  in  a  platinum  crucible  of  20 
cubic  centimeters  capacity.  The  crucible  should  have  a  tightly 
fitting  cover  as  above.  The  crucible  is  placed  in  the  flame  of 
a  Meker  burner,  size  No.  4,  having  approximately  an  outside 
diameter  at  the  top  of  25  millimeters  and  giving  a  flame  not 
less  than  15  centimeters  high.  The  temperature  should  be 


FIG.  2. 


i6 


from  900  to  950°  C.,  determined  by  placing  a  thermo-couple 
through  the  perforated  cover,  which  for  this  purpose  may  be 
of  nickel.  The  junction  of  the  couple  should  be  placed  in 
contact  with  the  center  of  the  bottom  of  the  crucible;  or  the 
temperature  may  be  indicated  by  the  fusion  of  pure  potassium 
chromate  in  the  covered  crucible  (fusion  of  K2CrO4,  940°  C.). 


FIG.  3. 


The  crucible  is  placed  in  the  flame  about  i  centimeter  above 
the  top  of  the  burner  and  the  heating  is  continued  for  7  min- 
utes. After  the  main  part  of  the  gases  have  been  discharged 
the  cover  should  be  tapped  into  place  as  above  described. 


17 

When  the  gas  pressure  is  variable  it  is  well  to  use  a  U-tube 
attachment  to  the  burner  to  show  the  pressure. 

Mechanical  losses  are  incurred  on  suddenly  heating  peat, 
sub-bituminous  coal,  and  lignite;  therefore  they  must  be  sub- 
jected to  a  preliminary  gradual  heating  for  5  minutes;  this  is 
best  done  by  playing  the  flame  of  a  burner  upon  the  bottom  of 
the  crucible  in  such  a  manner  as  to  bring  about  the  discharge 
of  volatile  matter  at  a  rate  not  sufficient  to  cause  sparking. 
After  the  preliminary  heating,  transfer  the  crucible  to  the  vol- 
atile matter  furnace  or  place  in  the  full  flame  of  the  Meker 
burner  and  heat  for  6  minutes  at  950°  C.,  as  in  the  regular 
method. 

The  allowable  variations  are  as  follows : 

Same  analyst  Different  analyst 

per  cent.  per  cent. 

Bituminous  coals 0.5  i.o 

Lignites I .o  2.0 

Notes. — The  cover  should  fit  closely  enough  so  that  the  car- 
bon deposit  from  bituminous  and  lignite  coals  does  not  burn 
away  from  the  under  side. 

Regulation  of  temperature  to  within  prescribed  limits  is  im- 
portant. 

Determination  of  Fixed  Carbon  and  Ash. 
APPARATUS. 

Gas  or  Electric  Muffle  Furnace. — The  muffle  should  have  a 
good  air  circulation  and  be  capable  of  having  its  temperature 
regulated  between  700°  and  750°  C. 

Porcelain  Capsules. — Royal  Meissen  Porcelain  Capsules  No. 
2,  y%  inch  de.ep  and  ify  inches  in  diameter,  or  similar  shallow 
dishes. 

METHOD. 

Place  the  porcelain  capsules  containing  the  dried  coal  from 
the  moisture  determination  in  a  cold  muffle  furnace,  or  on 
the  hearth  at  a  low  temperature,  and  gradually  heat  to  redness 
at  such  a  rate  as  to  avoid  mechanical  loss  from  too  rapid  ex- 
pulsion of  volatile  matter. 


i8 

Finish  the  ignition  to  constant  weight  ( — o.ooi  gram)  at  a 
temperature  between  700°  and  750°  C.  Cool  in  air  and  weigh 
as  soon  as  cold.  Coals  containing  carbonate  are  best  cooled 
in  a  desiccator. 

The  results  as  determined  by  this  method  represent  the 
ignited  mineral  matter  in  the  coal.  The  actual  mineral  matters 
in  the  original  coal  are  usually  very  different  in  weight  and 
composition.  The  application  of  corrections  for  sulphur  pres- 
ent in  the  iron  pyrites  and  for  the  volatile  ash  constituent  due 
to  hydration  of  clayey  material,  may  be  omitted  for  technical 
purposes.  For  "corrected"  ash  see  Jour.  Ind.  and  Eng.  Chem., 
Vol.  5,  June,  1913,  p.  523,  and  Technical  Paper  No.  f6,  Bureau 
of  Mines. 

The  allowable  variations  are  as  follows : 

Same  analyst  Different  analyst 

per  cent.  per  cent. 

No  carbonates  present 0.2  0.3 

Carbonates  present 0.3  0.5 

Coals  with  more  than  12%  of  ash 

containing  carbonates  and  py- 

rite 0.5  i  .o 

FIXED  CARBON. 

Compute  as  follows : 

100  :=  (moisture  +  ash  +  volatile  matter)  —  percentage  of 
fixed  carbon. 

SULPHUR. 

ESCHKA  METHOD. 

Apparatus. 

Gas  or  Electric  Muffle  Furnace,  or  Burners. — For  igniting 
coal  with  Eschka  mixture  and  for  igniting  the  barium  sulphate. 

Porcelain,  Silica,  or  Platinum  Crucibles  or  Capsules. — For 
igniting  coal  with  the  Eschka  mixture. 

No.  i. — Royal  Meissen  porcelain  capsule,  I  inch  deep  and  2 
inches  in  diameter.  This  capsule  because  of  its  shallow  form, 
presents  more  surface  for  oxidation  and  is  more  convenient 
to  handle  than  the  ordinary  form  of  crucible. 


19 

No.  i. — Royal  Berlin  porcelain  crucibles,  shallow  form,  and 
platinum  crucibles  of  similar  size  may  be  used.  Somewhat 
more  time  is  required  to  burn  out  the  coal  owing  to  the  deeper 
form,  than  with  the  shallow  capsules  described  above. 

No.  o  or  oo  porcelain  crucibles,  or  platinum,  alundum  or 
silica  crucibles  of  similar  size  are  to  be  used  for  igniting  the 
barium  sulphate. 

SOLUTIONS  AND  REAGENTS. 

Barium  Chloride. — Dissolve  100  grams  of  barium  chloride 
in  1,000  cubic  centimeters  of  distilled  water. 

Saturated  Bromine  Water. — Add  an  excess  of  bromine  to 
1,000  cubic  centimeters  of  distilled  water. 

Eschka  Mixture. — Thoroughly  mix  two  parts  (by  weight) 
of  light  calcined  magnesium  oxide  and  one  part  of  anhydrous 
sodium  carbonate.  Both  materials  should  be  as  free  as  possi- 
ble from  sulphur. 

Methyl  Orange. — Dissolve  0.02  gram  in  100  cubic  centi- 
meters of  hot  distilled  water  and  filter. 

Hydrochloric  Acid. — Mix  500  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20  and  500  cubic  centimeters  of 
distilled  water. 

Normal  Hydrochloric  Acid. — Dilute  80  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20  to  I  liter  with  distilled 
water. 

Sodium  Carbonate. — A  saturated  solution,  approximately  60 
grams  of  crystallized  or  22  grams  of  anhydrous  sodium  car- 
bonate in  100  cubic  centimeters  of  distilled  water. 

Sodium  Hydroxide  Solution. — Dissolve  100  grams  in  I  liter 
of  distilled  water.  This  solution  may  be  used  in  place  of  the 
sodium  carbonate  solution. 

METHOD. 

Preparation  of  Sample  and  Mixture. — Thoroughly  mix  on 
glazed  paper  I  gram  of  coal  and  3  grams  of  Eschka  mixture. 
Transfer  to  the  crucible  or  capsule  and  cover  with  about  I 
gram  of  Eschka  mixture. 


20 

Ignition. — On  account  of  the  amount  of  sulphur  contained 
in  artificial  gas,  it  is  preferable  to  heat  the  crucible  over  an 
alcohol  flame  or  in  an  electrically  heated  muffle,  as  in  (a)  fol- 
lowing. The  use  of  artificial  gas  is  permissible  only  when 
crucibles  are  heated  in  a  muffle  as  in  (b)  following. 

(a)  Heat  the  crucible,  placed  in  a  slanting  position  on  a 
triangle,  over  a  very  low  flame  to  avoid  rapid  expulsion  of 
the  volatile  matter,  which  tends  to  prevent  complete  absorp- 
tion of  the  products  of  combustion  of  the  sulphur.     Heat  the 
crucible  slowly  for  30  minutes,  gradually  increasing  the  tem- 
perature and  stirring  after  all  black  particles  have  disappeared, 
which  is  an  indication  of  the  completeness  of  the  procedure. 

(b)  Place  the  crucible  in  a  cold  gas  muffle  and  gradually 
raise  the  temperature  to  87o°-925°   C.    (cherry-red  heat)   in 
about  i  hour.     Maintain  the  maximum  temperature  for  about 
ij/2  hours  and  then  allow  the  crucible  to  cool  in  the  muffle. 

Subsequent  Treatment. — Remove  and  empty  the  contents 
into  a  200  cubic  centimeter  beaker  and  digest  with  100  cubic 
centimeters  of  hot  water  for  ^<  to  ^4  hour,  with  occasional 
stirring.  Filter  and  wash  the  insoluble  matter  by  decantation. 
After  several  washings  in  this  manner,  transfer  the  insoluble 
matter  to  the  filter  and  wash  five  times,  keeping  the  mixture 
well  agitated.  Treat  the  filtrate  amounting  to  about  250  cubic 
centimeters,  with  10  to  20  cubic  centimeters  of  saturated 
bromine  water,  make  slightly  acid  with  hydrochloric  acid  and 
boil  to  expel  liberated  bromine.  Make  just  neutral  to  methyl 
orange  with  sodium  hydroxide  or  sodium  carbonate  solution. 
Then  add  I  cubic  centimeter  of  normal  hydrochloric  acid. 
Boil  again  and  add  slowly  from  a  pipette,  with  constant 
stirring,  10  cubic  centimeters  of  a  10  per  cent,  solution  of 
barium  chloride.  Continue  boiling  for  15  minutes  and  allow 
to  stand  for  at  least  2  hours,  or  preferably  over  night  at  a 
temperature  just  below  boiling.  Filter  through  an  ashless  filter 
paper  and  wash  with  hot  distilled  w^ater  until  a  silver  nitrate 
solution  shows  no  precipitate  writh  a  drop  of  the  filtrate.  Place 
the  wet  filter  containing  the  precipitate  of  barium  sulphate  in 


21 


a  weighed  platinum,  porcelain,  silica  or  alundum  crucible, 
allow  a  free  access  of  air  by  folding  the  paper  over  the  precip- 
itate loosely  to  prevent  spattering.  Smoke  the  paper  off  grad- 
ually and  at  no  time  allow  it  to  burn  with  a  flame.  After  the 
paper  is  practically  consumed,  raise  the  temperature  to  approx- 
imately 925°  C.,  and  heat  to  constant  weight.  The  residue 
of  magnesia,  etc.,  after  bleaching,  should  be  dissolved  in  hydro- 
chloric acid  and  tested  with  great  care  for  sulphur.  When  an 
appreciable  amount  is  found  it  should  be  determined  quanti- 
tatively.4 

Blanks  and  Corrections. — In  all  cases  a  correction  must  be 
applied  either  (i)  by  running  a  blank  exactly  as  described 
above,  using  the  same  amount  of  all  reagents  that  were  em- 
ployed in  the  regular  determination  or  (2)  by  determining  a 
known  amount  of  sulphate  added  to  a  solution  of  the  reagents 
after  these  have  been  put  through  the  prescribed  series  of 
operation.  If  this  latter  procedure  is  adopted  and  carried 
out,  say,  once  a  week  or  whenever  a  new  supply  of  a  reagent 
must  be  used,  and  for  a  series  of  solutions  covering  the  range 
of  sulphur  content  likely  to  be  met  with  in  coals,  it  is  only 
necessary  to  add  to  or  subtract  from  the  weight  of  barium 
sulphate  obtained  from  a  coal.  Whatever  deficiency  or  excess 
may  have  been  found  in  the  appropriate  "check"  in  order  to 
obtain  a  result,  that  is  more  certain  to  be  correct  than  if  a 
"blank"  correction  as  determined  by  the  former  procedure  is 
applied.  This  is  due  to  the  fact  that  the  solubility  error  for 
barium  sulphate,  for  the  amounts  of  sulphur  in  question  and 
the  conditions  of  precipitation  prescribed,  is  probably  the 
largest  one  to  be  considered.  Barium  sulphate  is  soluble  in 
acids5  and  even  in  pure  water,  and  the  solubility  limit  is  reached 
almost  immediately  on  contact  with  the  solvent.  Hence,  in  the 
event  of  using  reagents  of  very  superior  quality  or  of  exercis- 
ing more  than  ordinary  precautions,  there  may  be  no  apparent 
"blank"  because  the  solubility  limit  of  the  solution  for  barium 
sulphate  has  not  been  reached  or  at  any  rate  not  exceeded. 

4  Journal  American  Chemical  Society,  Volume  21,  page  1125  (1899). 

5  Jour.  Am.  Chern.  Soc.  Vol.  32,  p.  588  (1910);  Vol.  33,  p.  829,  (1911). 


22 


ATKINSON  METHOD. 

Thoroughly  mix  on  glazed  paper  I  gram  of  the  laboratory 
sample  of  coal  with  7  grams  of  dry  sodium  carbonate  and 
spread  evenly  over  the  bottom  of  a  shallow  platinum  or  por- 
celain dish.  Place  on  a  triangle  slightly  elevated  above  the 
bottom  of  a  cold  muffle.  Heat  the  muffle  gradually  until  a  tem- 
perature of  650°  to  700°  C.  (dull  red  heat)  has  been  obtained 
in  half  an  hour  and  maintain  this  temperature  for  10  or  15 
minutes. 

The  sodium  carbonate  should  not  sinter  or  fuse.  The  mix- 
ture should  not  be  stirred  during  the  heating  process.  When 
the  dish  has  cooled  sufficiently  to  handle,  the  matter  should  be 
examined  for  black  particles  of  unburned  carbon  and  in  case 
such  indications  of  incompleteness  of  the  process  should  ap- 
pear the  dish  should  be  replaced  and  heated  for  a  short  time. 
When  all  the  carbon  is  burned,  remove  the  dish  and  digest  the 
contents  with  100  to  125  cubic  centimeters  of  warm  water  and 
5  cubic  centimeters  of  concentrated  hydrochloric  acid.  Allow 
the  insoluble  matter  to  settle,  decant  through  a  filter  and  wash 
several  times  by  decantation.  Transfer  to  the  filter  adding  a 
few  drops  of  a  solution  of  pure  sodium  chloride  if  the  insoluble 
matter  tends  to  pass  through  the  filter.  The  washings  should 
be  continued  until  the  filtrate  shows  no  alkaline  reaction. 
Make  the  filtrate  just  acid  to  methyl  orange,  add  I  cubic 
centimeter  of  normal  hydrochloric  acid  and  proceed  as  de- 
scribed under  Eschka  method. 

THE  PEROXIDE  FUSION  METHOD. 

This  method  is  most  conveniently  carried  out  in  the  Parr 
Calorimeter.  The  charge  consists  of  0.5  gram  of  the  air-dry 
laboratory  sample  of  coal,  I  gram  of  potassium  chlorate  pul- 
verized to  about  2o-mesh,  and  10  grams  of  sodium  peroxide 
of  the  grade  regularly  prescribed  for  calorimetric  purposes. 
The  coal  and  potassium  chlorate  are  first  added  to  the  bomb 
or  fusion  cup  and  thoroughly  mixed,  being  careful  to  break 
down  any  lumps  that  may  form.  The  sodium  peroxide  is  then 


23 

added,  the  container  closed  and  the  ingredients  thoroughly 
mixed  by  shaking. 

After  igniting  and  cooling  the  charge,  dissolve  the  fusion 
in  a  covered  beaker,  using  150  cubic  centimeters  of  water. 
Add  concentrated  hydrochloric  acid  just  past  the  neutral 
point  (25  to  30  cubic  centimeters).  Add  I  cubic  centimeter 
of  concentrated  hydrochloric  acid  (specific  gravity  1.19)  in  ex- 
cess. Filter  and  wash  with  hot  water,  making  the  final  bulk  of 
the  solution  approximately  250  cubic  centimeters.  Heat  to  boil- 
ing and  precipitate  the  sulphate  by  adding  10  cubic  centi- 
meters of  a  10  per  cent,  solution  of  barium  chloride.  Proceed 
as  described  under  Eschka  method. 

Particular  care  should  be  taken  in  washing  the  precipitate 
obtained  by  this  method  in  order  to  remove  all  of  the  soluble 
salts  which  are  formed  in  the  fusion  process. 

Determination  of  Sulphur  in  the  Bomb  Washings. 

Where  the  precise  content  of  sulphur  is  not  required  it  may 
be  approximated  from  the  washings  from  an  oxygen  bomb 
calorimeter  as  follows : 

After  the  combustion,  the  bomb  is  washed  out  thoroughly 
with  distilled  water,  and  the  washings  collected  in  a  250  cubic 
centimeter  beaker.  Six  to  eight  cubic  centimeters  of  dilute 
(1:1)  hydrochloric  acid  containing  some  bromine  water  are 
then  added  and  the  solution  is  heated  to  boiling.  The  insoluble 
matter  is  filtered  off  and  washed  free  from  sulphates  with  hot 
water.  The  filtrate  and  washings  which  should  have  a  total 
volume  of  200  cubic  centimeters  are  made  just  neutral  to 
methyl  orange  with  sodium  hydroxide  or  carbonate  solution, 
i  cubic  centimeter  of  normal  hydrochloric  acid  is  added,  and 
the  procedure  completed  as  described  under  Eschka  method. 

The  allowable  variations  in  sulphur  determinations  are  as 
follows : 

Same  analyst  Different  analyst 

per  cent.  per  cent. 

For  coal 0.05  o.i 

For  coke 0.03  0.05 


24 

Determination  of  Phosphorus.     (Recommended  by 
Committee  E-4.) 

To  the  ash  from  5  grams  of  coal  in  a  platinum  capsule  is 
added  10  cubic  centimeters  of  nitric  acid  and  3  to  5  cubic 
centimeters  of  hydrofluoric  acid.  The  liquid  is  evaporated  and 
the  residue  fused  with  3  grams  of  sodium  carbonate.  If  un- 
burned  carbon  is  present  0.2  gram  of  sodium  nitrate  is  mixed 
with  the  carbonate.  The  melt  is  leached  with  water  and  the 
solution  filtered.  The  residue  is  ignited,  fused  with  sodium 
carbonate  alone,  the  melt  leached  and  the  solution  filtered. 
The  combined  filtrates,  held  in  a  flask,  are  just  acidified  with 
nitric  acid  and  concentrated  to  a  volume  of  100  cubic  centi- 
meters. 

To  the  solution,  brought  to  a  temperature  of  85°  C.,  is  added 
50  cubic  centimeters  of  molybdate  solution  and  the  flask  is 
shaken  for  10  minutes.  The  precipitate  is  washed,  on  a  filter, 
six  times,  or  until  free  from  acid,  with  a  2  per  cent,  solution 
of  potassium  nitrate,  then  returned  to  the  flask  and  titrated 
with  standard  sodium  hydroxide  solution.  The  alkali  solution 
may  well  be  made  equal  to  0.00025  gram  phosphorus  per  cubic 
centimeter  or  0.005  Per  cent-  f°r  a  5  gram  sample  of  coal,  and 
is  0.995  of  one-fifth  normal,  (i)  Or  the  phosphorus  in  the 
precipitate  is  determined  by  reduction  and  titration  of  the 
molybdenum  with  permanganate. 

The  advantage  of  the  use  of  hydrofluoric  acid  lies  in  the 
removal  of  silica.  Fusion  with  alkali  carbonate  is  necessary 
for  the  elimination  of  titanium,  which  if  present  and  not  re- 
moved with  contaminate  the  phospho-molybdate  and  is  said  to 
sometimes  retard  its  precipitation. 

Ultimate  Analysis. 
CARBON  AND  HYDROGEN. 

The  determination  of  carbon  and  of  hydrogen  is  made  with 
a  weighed  quantity  of  sample  in  a  25-burner  combustion  fur- 
nace of  the  Glaser  type.  The  products  of  combustion  are 
thoroughly  oxidized  by  being  passed  over  red-hot  copper  oxide 


25 

and  lead  chromate,  and  are  fixed  by  absorbing  the  water  in  a 
weighed  Marchand  tube  filled  with  granular  calcium  chloride 
(CaCl2)  and  by  absorbing  the  carbon  dioxide  in  a  Liebig  bulb 
containing  a  3<>per  cent,  solution  of  potassium  hydroxide 
(KOH). 

The  apparatus  used  consists  of  a  purifying  train,  in  dupli- 
cate, a  combustion  tube  in  the  furnace,  and  an  absorption  train. 
The  purifying  train  consists  of  the  following  purifying  re- 
agents arranged  in  order  of  passage  of  air  and  oxygen  through 
them:  Sulphuric  acid,  potassium  hydroxide  solution,  soda 
lime  and  granular  calcium  chloride.  One  of  the  trains  is  for 
air  and  one  for  oxygen.  In  the  sulphuric  acid  and  potassium 
hydroxide  scrubbing  bottles  the  air  and  the  oxygen  are  made 
to  bubble  through  about  5  millimeters  of  the  purifying  reagent. 
Both  purifying  trains  are  connected  to  the  combustion  tube  by 
a  Y-tube,  the  joint  being  made  tight  by  a  rubber  stopper. 

The  combustion  tube  may  be  of  hard  Jena  glass,  quartz  or 
fused  silica.  Its  external  diameter  is  about  21  millimeters, 
and  its  total  length  is  i  meter.  The  first  30  centimeters  of 
the  tube  are  empty :  following  this  empty  space  is  an  asbestos 
plug  (acid  washed  and  ignited)  or  in  its  place  a  roll  of  oxi- 
dized copper  gauze  may  be  used;  the  next  40  centimeters  are 
filled  with  copper  oxide  wire ;  a  second  asbestos  plug  separates 
the  copper  oxide  from  10  centimeters  of  fused  lead  chromate, 
which,  is  held  in  place  by  another  asbestos  plug  20  centimeters 
from  the  end  of  the  tube.  The  end  of  the  tube  is  contracted 
for  rubber  tubing  connection  with  the  absorbing  train. 

The  absorption  train  consists,  first,  of  a  Marchand  tube 
filled  with  granular  calcium  chloride  (CaCl2)  to  absorb  moist- 
ure. The  CaCl2  should  be  saturated  with  CO2  before  using 
The  Marchand  tube  is  followed  by  a  Liebig  bulb  containing  a 
3O-per  cent,  potassium  hydroxide  solution,  in  which  any  pos- 
sible impurities,  as  ferrous  iron  or  nitrates,  have  been  oxidized 
by  a  little  potassium  permanganate  (KMnO4).  A  guard  tube 
containing  granular  calcium  chloride  and  soda  lime  is  attached 
to  the  Liebig  bulb  to  absorb  any  dioxide  escaping  the  potassium 


26 

hydroxide  solution  and  any  water  evaporating  from  that  solu- 
tion. 

The  train  is  connected  to  an  aspirator  which  draws  the 
products  of  combustion  through  the  entire  train.  A  guard 
tube  of  calcium  chloride  prevents  moisture  from  running  back 
into  the  absorption  train.  The  suction  is  maintained  constant 
by  a  Mariotte  flask.  The  advantage  of  aspirating  the  gases 
through  the  train  rather  than  forcing  them  through  by  pressure 
is  that  the  pressure  on  the  rubber  connections  is  from  the  out- 
side, so  that  gas-tight  connections  are  more  easily  maintained 
than  if  the  pressure  is  on  the  inside  of  the  tube.  The  connec- 
tions are  made  as  tight  as  possible. 

The  usual  test  for  tightness  is  to  start  aspiration  at  the  rate 
of  about  three  bubbles  of  air  per  second  through  the  potash 
bulb,  and  then  to  close  the  inlet  for  air  and  oxygen  at  the 
opposite  end  of  the  train ;  if  there  is  no  more  than  one  bubble 
per  minute  in  the  potash  bulb,  the  apparatus  is  considered  tight. 
Before  starting  a  determination  when  the  train  has  been  idle 
some  hours,  or  after  any  changes  in  chemicals  or  connections, 
a  blank  is  run  by  aspirating  about  I  liter  of  air  through  the 
train,  which  is  heated  in  the  same  manner  as  if  a  determination 
on  coal  were  being  made.  If  the  Liebig  bulb  and  tube  contain- 
ing calcium  chloride  show  a  change  in  weight  of  less  than  0.5 
milligram  each  the  apparatus  is  in  proper  condition  for  use. 

A  porcelain  or  platinum  boat  is  provided  with  a  glass  weigh- 
ing tube  of  suitable  size,  which  is  fitted  with  an  accurately 
ground  glass  stopper.  The  tube  and  empty  boat  are  weighed. 
Approximately  0.2  gram  of  the  air-dry  coal  (6omesh  or 
preferably  loo-mesh)  are  quickly  placed  in  the  boat.  The  boat 
is  at  once  placed  in  the  weighing  tube,  which  is  quickly  stop- 
pered to  prevent  moisture  change  in  the  coal  while  weighing, 
and  transferring  to  the  furnace.  The  absorption  tubes  are 
connected  and  the  boat  and  sample  are  transferred  as  quickly 
as  possible  from  the  weighing  tube  to  the  combustion  tube, 
which  should  be  cool  for  the  first  30  centimeters.  The  copper 
oxide  should  at  this  time  be  red  hot  and  the  lead  chromate  at  a 
dull  red  heat.  As  soon  as  the  boat  is  in  place  (near  the  as- 


27 

bestos  plug  at  the  beginning  of  the  copper  oxide)  the  stopper 
connecting  with  the  purifying  train  is  inserted  and  the  aspir- 
ation started  with  pure  oxygen  gas  at  the  rate  of  three  bubbles 
per  second.  One  burner  is  turned  on  about  10  centimeters 
back  from  the  boat,  and  the  aspiration  is  continued  carefully 
until  practically  all  the  moisture  is  expelled  from  the  sample. 
The  heat  is  then  increased  very  gradually  until  all  the  volatile 
matter  has  been  driven  off.  In  driving  off  the  volatile  matter 
the  heat  must  be  applied  gradually  in  order  to  prevent  a  too 
rapid  evolution  of  gas  and  tar,  which  may  either  escape  com- 
plete combustion  or  may  be  driven  back  into  the  purifying 
train. 

The  heat  should  be  slowly  increased  by  turning  on  more 
burners  under  the  open  part  of  the  tube  until  the  sample  is 
ignited :  after  which  the  temperature  may  be  increased  rapidly, 
but  care  should  be  taken  not  to  melt  the  combustion  tube  if  a 
glass  one  is  being  used.  Any  moisture  collecting  in  the  end  of 
the  combustion  tube  or  in  the  rubber  connection  joining  it  to 
the  calcium  chloride  tube  is  driven  over  into  the  calcium  chlo- 
ride tube  by  carefully  warming  with  a  piece  of  hot  tile.  The 
aspiration  with  oxygen  is  continued  for  two  minutes  after  the 
sample  ceases  to  glow,  the  heat  is  then  turned  off  and  about 
1,200  cubic  centimeters  of  air  are  aspirated.  The  absorption 
bulbs  are  then  disconnected,  wiped  with  a  clean  cloth  and 
allowed  to  cool  to  the  balance  room  temperature  before  weigh- 
ing. 

Percentage  of  hydrogen  = 

11.19  X  increase  in  weight  of  CaCl2  tube 

Weight  of  sample. 
Percentage  of  carbon  = 

27.27  X  increase  in  weight  of  KOHbulb 

Weight  of  sample. 

The  ash  in  the  boat  is  weighed  and  carefully  inspected  for 
any  unburned  carbon. 

Method  with  Electrically  Heated  Combustion  Furnace. 
For  description  of  furnace  and  method  see  Technical  Paper 
No.  8,  Bureau  of  Mines,  revised  edition  1913,  p.  22. 


28 


Nitrogen. 

The  Kjeldahl-Gunning  Method. — One  gram  of  the  coal 
sample  (coke  and  anthracite  should  be  ground  to  an  inpalpable 
powder)  is  boiled  with  30  cubic  centimeters  of  concentrated 
sulphuric  acid  (H2SO4),  7  to  10  grams  of  potassium  sulphate 
(K2SO4),  and  0.6  to  0.8  gram  of  metallic  mercury  in  a  500' 
cubic  centimeter  Kjeldahl  flask  until  all  particles  of  coal  are 
oxidized  and  the  solution  nearly  colorless.  The  boiling  should 
be  continued  for  2  hours  after  the  straw  colored  stage  has  been 
reached.  The  total  time  of  digestion  will  be,  for  coal,  from 
3  to  4  hours  and  for  coke  and  anthracite  may  be  from  12  to  16 
hours.  The  addition  of  a  few  crystals  of  potassium  perman- 
ganate (KMnO4),  after  the  solution  has  been  cooled  enough 
to  avoid  violent  reaction,  tends  to  insure  complete  oxidation. 

After  cooling,  the  solution  is  diluted  to  about  200  cubic  centi- 
meters with  cold  water.  If  the  dilution  with  water  has 
warmed  the  solution,  it  should  be  again  cooled  and  the  follow- 
ing reagents  added:  25  cubic  centimeters  potassium  sulphide 
(K2S)  solution  (40  grams  K,2S  per  liter)  to  precipitate  the 
mercury  and  so  prevent  the  formation  of  mercurammonium 
compounds  Which  are  not  completely  decomposed  by  sodium 
hydroxide,  I  to  2  grams  of  granular  zinc  to  prevent  bumping, 
and  finally  enough  strong  sodium  hydroxide  (NaOH)  solution 
(usually  80  to  100  cubic  centimeters)  to  make  the  solution  dis- 
tinctly alkaline.  The  danger  of  loss  of  ammonia  may  be  mini- 
mized by  holding  the  flask  in  an  inclined  position  while  the 
sodium  hydroxide  solution  is  being  added.  The  alkaline  solu- 
tion runs  down  the  side  of  the  flask  and  forms  a  layer  below 
the  lighter  acid  solution.  After  adding  the  alkaline  solution, 
the  flask  is  at  once  connected  to  the  condensing  apparatus  and 
the  solution  mixed  by  gently  shaking  the  flask. 

The  ammonia  (NH3)  is  distilled  over  into  a  measured 
amount  of  standard  sulphuric  acid  solution  to  which  has  been 
added  sufficient  cochineal  indicator  for  titration.  Care  should 
be  taken  that  the  glass  connecting  tube  on  the  end  of  the  con- 
denser dips  under  the  surface  of  the  standard  acid.  The  solu- 


29 

tion  is  slowly  distilled  over  until  150  to  200  cubic  centimeters 
of  distillate  has  passed  over.  To  avoid  mechanically  entrained 
alkali  passing  over  into  the  condenser  the  rate  of  distillation 
should  not  exceed  100  cubic  centimeters  per  hour.  The  dis- 
tillate is  titrated  with  standard  ammonia  solution.  Standard 
NaOH  or  KOH  solution  with  methyl  orange,  methyl  red  or 
sodium  alizarin  sulphonate  as  indicator  may  be  used  instead  of 
ammonia  and  cochineal. 

A  blank  determination  should  be  made  in  the  same  manner 
as  described  above,  except  that  i  gram  of  pure  sucrose  (cane 
sugar)  is  substituted  for  the  coal.  The  nitrogen  found  in 
this  blank  is  deducted  from  the  result  obtained  with  the  coal. 

Oxygen. 

Oxygen  is  computed  by  subtracting  the  sum  of  the  per- 
centages of  hydrogen,  carbon,  nitrogen,  sulphur,  water  and  ash 
from  100.  The  result  so  obtained  is  affected  by  all  the  errors 
incurred  in  the  other  determinations  and  especially  by  the 
change  in  weight  of  the  ash  forming  constituents  on  ignition. 

A  more  nearly  correct  oxygen  value  may  be  obtained  by 
making  the  corrections  indicated  here. 

Corrected  oxygen  =  100  —  (C  —  C')  +  (H  —  H')  +  N  + 
H2O  +  S'  +  corrected  ash. 

In  which  C       =  total  carbon 

C'      =  carbon  of  carbonates 

H      =  total  hydrogen  less  hydrogen  of  water 

H'     =  hydrogen   from  water  of   composition  in 
clay,  shale,  etc. 

N      =  nitrogen 

H2O  =  moisture  as  found  at  105°  C. 

S       =  sulphur  not  present  as  pyrite  or  sulphate. 

This  is  usually  small. 
3 


30 

Corrected  Ash  =  Mineral  constituents  originally 
present  in  the  coal.  For  most 
purposes  this  can  be  determined 
with  sufficient  accuracy  by,  add- 
ing to  the  ash,  as  found,  five- 
eights  of  the  weight  of  pyritic 
sulphur,  the  CO2  of  carbonates 
,  and  the  water  of  composition  of 
clay,  shale,  etc. 

Calorimetric  Determination . 
APPARATUS. 

Combustion  Bombs.6 — The  Atwater,  Davis,  Emerson,  Mah- 
ler, Parr,  Peters,  Williams,  or  similar  bombs  may  be  used. 
The  bomb  shall  have  an  inner  surface  of  platinum,  gold,  porce- 
lain enamel,  or  other  material  which  is  not  attacked  by  nitric 
and  sulphuric  acids,  or  other  products  of  combustion. 

Calorimeter  Jacket. — The  calorimeter  must  be  provided 
with  a  water-jacket  having  a  cover  to  protect  the  calorimeter 
from  air  currents.  The  jacket  must  be  kept  filled  with  water 
within  2  or  3°  C.  of  the  temperature  of  the  room  (except  in 
calorimeters  which  are  totally  submerged,  where  the  jacket 
temperature  is  controlled  by  a  thermostat)  and  should  be 
stirred  continuously  by  some  mechanical  stirring  device. 

Stirring  of  the  Calorimeter  Water. — The  water  in  the  calo- 
rimeter must  be  stirred  sufficiently  well  to  give  consistent  ther- 
mometer readings  while  the  temperature  is  rising  rapidly.  The 
speed  of  stirring  should  be  kept  constant.  A  motor-driven 
screw  or  turbine  stirrer  is  recommended  and  the  speed  should 
not  be  excessive.  This  may  be  determined  by  adjusting  the 
temperature  of  the  calorimeter  to  equality  with  that  of  the 
jacket  and  allowing  the  stirrer  to  run  continuously  for  10 
minutes.  If  the  temperature  of  the  calorimeter  rises  more 
than  about  0.01°  C.  in  this  length  of  time,  the  rate  of  stirring 

6  "The  Committee  recommends  the  oxygen  bomb.  Where  no  oxygen  bomb  calo- 
rimeter is  available,  the  Parr,  when  carefully  handled  (preferably  with  electric  igni- 
tion and  in  conjunction  with  a  Beckman  thermometer)  will  give  satisfactory  results." 


is  excessive.  Accurate  results  cannot  be  obtained  when  too 
much  energy  is  supplied  by  the  stirring  device  or  when  the 
rate  of  stirring  is  irregular.  The  portion  of  the  stirring  device 
immersed  in  the  calorimeter  should  be  separated  from  the  out- 
side by  non-conducting  material,  such  as  hard  rubber,  to  pre- 
vent conduction  of  heat  from  the  motor  or  outside  air. 

Thermometers. — Thermometers  used  shall  have  been  certi- 
fied by  a  government  testing  bureau  and  shall  be  used  with  cor- 
rections given  on  the  certificate.  This  shall  also  apply  to  elec- 
trical resistance  or  thermo-electric  thermometers.  Correction 
shall  also  be  made  for  the  temperature  of  the  emergent  stem 
of  all  mercurial  thermometers,  and  for  the  "setting"  of  Beck- 
mann  thermometers.  For  accurate  work,  either  Beckmann  or 
special  calorimetric  thermometers  graduated  to  o.oi  or  0.02°  C. 
are  required.  Such  thermometers  should  be  tapped  lightly 
just  before  each  reading  to  avoid  errors  caused  by  the  sticking 
of  the  mercury  meniscus,  particularly  when  the  temperature  is 
falling.  A  convenient  method  is  to  mount  a  small  electric 
buzzer  directly  on  the  top  of  the  thermometer  and  connect  it 
up  with  a  dry  cell  and  a  push  button.  The  button  should  be 
pressed  for  a  few  seconds  immediately  before  each  reading. 

Oxygen. — The  oxygen  used  for  combustion  shall  be  free 
from  combustible  material.  If  an  approximation  of  the  sul- 
phur is  to  be  made  from  the  bomb  washings,  the  latter  when 
filled  should  contain  at  least  5  per  cent,  of  nitrogen.  The  total 
amount  of  oxygen  contained  in  the  bomb  for  a  combustion 
shall  not  be  less  than  5  grams  per  gram  of  coal.  But  the  com- 
bustion must  be  complete  as  shown  by  the  absence  of  any 
sooty  deposit  on  opening  the  bomb  after  firing. 

Firing  Wire. — The  coal  in  the  bomb  may  be  ignited  by  means 
of  either  iron  or  platinum  wire.  If  iron  wire  is  used  it  should 
be  of  about  No.  34  B  &  S  gauge  and  not  more  than  10  centi- 
meters should  be  used  at  a  time.  A  correction  of  1,600  calories 
per  gram  of  wire  burned  is  to  be  subtracted  from  the  ob- 
served number  of  calories. 

Standardization. — The  water  equivalent  of  a  calorimeter  can 
best  be  determined  by  the  use  of  standard  combustion  samples 


32 

supplied  by  the  Bureau  of  Standards.  The  required  water 
equivalent  is  equal  to  the  weight  of  the  sample  multiplied  by 
its  heat  of  combustion  per  gram  divided  by  the  corrected  rise 
in  temperature. 

The  calorimeter  shall  be  standardized  by  the  combustion  of 
standard  samples  supplied  by  the  Bureau  of  Standards,  and 
used  according  to  the  directions  given  in  the  certificates  which 
accompany  them.  A  standardization  shall  consist  of  a  series 
of  not  less  than  five  combustions  of  either  the  same  or  different 
standard  materials.  The  conditions  as  to  the  amount  of  water, 
oxygen,  firing  wire,  method  of  correcting  for  radiation,  etc., 
under  which  these  combustions  are  made  shall  be  the  same  as 
for  coal  combustions.  In  the  case  of  any  disagreement  be- 
tween contracting  parties  a  check  standardization  may  consist 
of  two  or  more  combustions  of  standardizing  samples. 

MANIPULATION. 

1.  Preparation  of  Sample. — The  ground  sample  is  to  be 
thoroughly  mixed  in  the  bottle  and  an  amount,  approximately 
i  gram,  is  to  be  taken  out  and  weighed  in  the  pan  or  crucible 
in  which  it  is  to  be  burned.     Coals  which  are  likely  to  be  blown 
out  of  the  crucible  should  be  briquetted.     For  anthracite  and 
coke  the  following  procedure  should  be  adopted:    The  inside 
of  the  crucible  is  lined  completely  with  a  thin  layer  of  ignited 
asbestos,  pressed  well  down  into  the  angles.     The  sample  is 
then  sprinkled  evenly  over  the  surface  of  the  asbestos.     After 
weighing,  the  sample  should  preferably  be  immediately  placed 
in  the  bomb  and  this  closed.     This  procedure  is  necessary  to 
avoid  sublimation  in  the  use  of  naphthalene  for  standardi- 
zation. 

2.  Preparation    of   the   Bomb. — The    firing   wire,    if    iron, 
should  be  measured  and  coiled  in  a  small  spiral  and  connected 
between  the  platinum  terminals,  using,  if  necessary,  a  piece  of 
platinum  wire  somewhat  heavier  than  the  iron  wire,  to  make 
the  connection.     The  platinum  and  the  iron  must  both  be  clean. 
About  0.5  cubic  centimeters  of  water  should  be  placed  in  the 
bottom  of  the  bomb  to  saturate  with  moisture  the  oxygen  used 


33 

for  combustion.  When  the  crucible  is  put  in  place  in  the 
bomb,  the  firing  wire  should  touch  the  sample.  For  combus- 
tion of  standardizing  materials,  or  for  coke,  iron  wire  is  prefer- 
able to  platinum. 

3.  Filling  the  Bomb  with  Oxygen. — Oxygen  from  the  supply 
tank  is  to  be  admitted  slowly  to  avoid  blowing  the  sample  from 
the  crucible  and  the  pressure  allowed  to  reach  20  atmospheres 
for  the  larger  bombs  or  about  30  atmospheres  for  the  smaller 
bombs,  so  that  the  bomb  shall  contain  an  amount  of  oxygen 
sufficient  for  complete  combustion,  namely  at  least  5  grams  per 
gram  of  coal  or  other  combustible.     For  coke  it  will  be  found 
better  to  allow  a  pressure  of  5  atmospheres  more  than  that  al- 
lowed for  coal. 

4.  Calorimeter  Water. — The  calorimeter  is  to  be  filled  with 
the  required  amount  of  distilled  water,  depending  upon  the 
type  of  calorimeter.     The  amount  may  be  determined  either 
by  measurement  in  a  standard  flask  or  by  weighing.     The 
amount  must  be  kept  the  same  as  that  used  in  standardization 
of  the  apparatus. 

5.  Temperature  Adjustments. — The   initial  temperature   in 
the  calorimeter  should  be  so  adjusted  that  the  final  temper- 
ature, after  the  combustion,  will  not  be  more  than  i°  C.,  pref- 
erably about  0.5°  C.,  above  that  of  the  jacket,  under  which 
conditions  the  total  correction  for  heat  gained  from  or  lost 
to  the  surroundings  will  be  small  when  the  rise  of  tempera- 
ture is  2  or  3°  C.,  and  the  effect  of  evaporation  will  also  be 
small. 

6.  Firing  Current. — The  electric  current  used  for  firing  the 
charge  should  be  obtained  from  storage  or  dry  cells  having  an 
electromotive  force  of  not  more  than  12  volts,  since  a  higher 
voltage  is  liable  to  cause  an  arc  between  the  firing  terminals, 
introducing  additional  heat,  which  cannot  be  measured  with 
certainty.     The  circuit  should  be  closed  by  means  of  a  switch, 
which   should   remain   closed   for   not  more  than   2   seconds. 
When  possible  it  is  recommended  that  an  ammeter  be  used  in 
the  firing  circuit  to  indicate  when  the  firing  wire  has  burned 
out. 


34 

7.  Method  of  Making  an   Observation. — The  bomb   when 
ready  for  firing  is  to  be  placed  in  the  calorimeter,  the  firing 
wires  connected,  the  cover  put  in  place  and  the  stirrer  and 
thermometer  so  placed  as  not  to  be  in  contact  with  the  bomb 
or  container.     The  stirrer  is  then  started  and  after  the  ther- 
mometer reading  has  become  steady,  not  less  than  2  minutes 
after  the  stirrer  is  started,  temperatures  are  read  at  I -minute 
intervals  for  5  minutes  and  the  charge  is  then  fired,  the  exact 
time  of  firing  being  noted.     Observations  of  temperature  are 
then  made  at  intervals  depending  upon  the  method  to  be  used 
for  computing  the  cooling  correction.     When  the  temperature 
has  reached  its  maximum  and  is  falling  uniformly,  a  series  of 
thermometer  readings   is  taken  at   i-minute  intervals   for   5 
minutes  for  determining  the  final  cooling  rate. 

8.  Titration. — After   the    combustion,   the   bomb    is   to   be 
opened,  after  allowing  the  gas  to  escape,  and  the  inside  ex- 
amined for  traces  of  unburned  material  or  sooty  deposit.     If 
these  are  found,  the  observations  shall  be  discarded.     If  the 
combustion  appears  complete,  the  bomb  is  to  be  rinsed  out 
thoroughly  and  the  washings  titrated  with  a  standard  alkali 
solution     (i     cubic    centimeter  =  0.02173    gram    HNO3  =  5 
calories)  using  methyl  orange  or  methyl  red  indicator,  to  de- 
termine the  amount   of   acid   formed.     A   correction   of   230 
calories  per  gram  of  nitric  acid  should  be  subtracted  from  the 
total  heat  observed. 

An  additional  correction  of  1,300  calories  per  gram  of  sul- 
phur in  the  coal  should  be  made  for  the  excess  of  difference 
in  heats  of  formation  of  SO2  and  aqueous  H2SO4  over  the  heat 
of  formation  of  aqueous  HNO3.  For  details  of  titration  see 
Technical  Paper  No.  8,  Bureau  of  Mines. 

Computation  of  Results. 

The  following  method  of  computation  is  recommended  to 
take  the  place  of  the  Pfaundler  or  other  similar  formulas  for 
computing  the  cooking  correction  (radiation  correction). 

Observe  (i)  the  rate  of  rise  (r)  of  the  calorimeter  tem- 
perature in  degrees  per  minute  for  5  minutes  before  firing; 


35 

(2)  the  time  (a)  at  which  the  last  temperature  reading  is  made 
immediately  before  firing;  (3)  the  time  (b)  when  the  rise  of 
temperature  has  reached  six-tenths  of  its  total  amount  (this 
point  can  generally  be  determined  by  .adding  to  the  temperature 
observed  before  firing,  60  per  cent,  of  the  expected  temperature 
rise,  and  noting  the  time  when  this  point  is  reached)  ;  (4)  the 
time  (c)  of  a  thermometer  reading  taken  when  the  tempera- 
ture change  has  become  uniform  some  5  minutes  after  firing; 
(5)  the  final  rate  of  cooling  (r2)  in  degrees  per  minute  for  5 
minutes. 

When  the  temperature  rise  is  not  approximately  known  be- 
forehand, it  is  only  necessary  to  take  thermometer  readings  at 
40,  50,  60  seconds  (and  possibly  70  seconds  with  some  calorim- 
eters) after  firing,  and  from  these  observations  to  find  when 
the  temperature  rise  has  reached  60  per  cent,  of  the  total. 
Thus,  if  the  temperature  at  firing  was  2.135°,  at  4°  seconds, 
3.05°,  at  50  seconds  3.92°,  at  60  seconds  4.16°,  and  the  final 
temperature  was  4.200°,  the  total  rise  was  2.07° ;  60  per  cent. 
of  it  was  1.24°.  The  temperature  to  be  observed  was  then 
2.14°  -j-  1.24°  =  3.38°.  Referring  to  the  observations  at  40 
and  50  seconds  the  temperatures  were  respectively  3.05°  and 
3.92°.  The  time  corresponding  to  the  temperature  of  3.38° 
was  therefore 

40  +  ^—  ~  3'°5  X  10  =  44  seconds. 
3.92  —  3.05 

The  rate  r  is  to  be  multiplied  by  the  time  b  —  a  in  minutes 
and  tenths  of  a  minute,  and  this  product  added  (subtracted 
if  the  temperature  was  falling  at  the  time  a)  to  the  thermom- 
eter reading  taken  at  the  time  a.  The  rate  r2  is  to  be  multi- 
plied by  the  time  c  —  b  and  this  product  added  (subtracted  if 
the  temperature  was  rising  at  the  time  c  and  later)  to  the 
thermometer  reading  taken  at  the  time  c.  The  difference  of 
the  two  thermometer  readings  thus  corrected,  provided  the 
corrections  from  the  certificate  have  already  been  applied, 
gives  the  total  rise  of  temperature  due  to  the  combustion.  This 
multiplied  by  the  water  equivalent  of  the  calorimeter  gives 
the  total  amount  of  heat  liberated. 


36 

The  result,  corrected  for  the  heats  of  formation  of  HNO3 
and  H2SO4  observed  and  for  the  heat  of  combustion  of  the 
firing  wire,  when  that  is  included,  is  to  be  divided  by  the 
weight  of  the  charge  to  find  the  heat  of  combustion  in  calories 
per  gram.  Calories  per  gram  multiplied  by  1.8  give  the  Brit- 
ish thermal  units  per  pound. 

In  practice,  the  time  b  —  a  will  be  found  so  nearly  constant 
for  a  given  calorimeter  with  the  usual  amounts  of  fuel  that  b 
need  be  determined  only  occasionally. 

The  results  should  be  reduced  to  calories  per  gram  or  Brit- 
ish thermal  units  per  pound  of  dry  coal,  the  moisture  being 
determined  upon  a  sample  taken  from  the  bottle  at  about  the 
same  time  as  the  combustion  sample  is  taken. 

EXAMPLE. 

Observations : 

Water  equivalent  =  2,550  grams.     Weight  of  charge  — 

1.0535. 

Approximate  rise  of  temperature  =  3.2°. 
60  per  cent,  of  approximate  rise  =  1.9°. 

Time  Temperature                                  Corrected  temperature 

10.21  15.244°         (Thermometer  corrections  from  the  certificate) 

.22  .250 

•23  -255 

.24  .261 

.25  .266 

(a)       .26  .272                                           15.276° 

Charge  Fired: 

>o°  (d) 

18.497° 


(b) 

27-2 

17.200* 

(c) 

31 

»  1  8.  500 

32 

.498 

33 

•  497 

34 

.496 

35 

•494 

36 

.493 

37 

Computation: 

ri  =  0.028°  -f  5  =  0.0056°  per  minute,     b  —  a  =  1.2  minutes 
The  corrected  initial  temperature  is 

15.276°  +  0.0056°  X  1.2  =  15-283° 

r:2  =  0.007°  H"  5  =  0.0014°  Per  minute;  c  —  b  =  3.8  minutes 
The  corrected  final  temperature  is  18.497°  -f-  (0.0014X3.8)  =  18.502° 

Total  rise  18.502°  —  15.283° =  3.219° 

Total  calories  2.550  X  3.219   =         8.209 

Titration,  etc.    —         0.007 

Calories  from  1.0535  g.  coal 8.202 

Calories  per  g 7,785 


or  British  thermal  units  per  pound r4>°!3 

(d)  The  initial  temperature  is  15.27°;  60  per  cent,  of  the  expected  rise 

is  1.9°. 
The  reading  to  observe  is  then  17.2°. 

The  results  obtained  by  the  above  method  of  computation 
and  determination  is  the  total  heat  of  combustion  at  constant 
volume,  with  the  water  in  the  products  of  combustion  con- 
densed to  liquid  at  the  temperature  of  the  calorimeter,  that  is, 
about  20°  to  35°  C. 

Net  heat  of  combustion  at  20°,  shall  refer  to  results  cor- 
rected for  latent  heat  of  vaporization,  as  follows : 

Total  heat  of  combustion  in  B.  t.  u.  --  1,040  (hydrogen  x 
9)  =  net  heat  of  combustion  in  B.  t.  u.  per  pound. 

Also  total  heat  of  combustion  in  calories  —  580  (hydrogen 
x  9  =  net  heat  of  combustion  in  calories  per  gram. 

Allowable  Variations: 

Per  cent. 
Same  analyst o.  3 

Different  analysts 0.5 

Shatter  Test  for  Coke. 

The  apparatus  consists  essentially  of  a  box  capable  of  hold- 
ing at  least  100  pounds  of  coke,  supported  with  the  bottom  6 
feet  above  a  cast-iron  plate.  The  doors  on  the  bottom  are  so 
hinged  and  latched  that  they  will  swing  clearly  away  when 
open  and  will  not  impede  the  fall  of  the  coke.  Boards  are 


38 

placed  around  the  cast-iron  plate  to  prevent  pieces  of  coke 
from  being  lost. 

Each  sample  is  approximately  50  pounds  and  is  selected  at 
random  using  a  2-inch  tine  fork.  The  sample  is  cool  when 
tested  but  not  artificially  dry. 

The  entire  sample  is  placed  in  the  box  and  dropped  on  the 
cast-iron  plate.  No  attempt  is  made  at  distributing  or  arrang- 
ing the  charge  in  the  box  before  dropping. 

The  entire  material  is  dropped  four  times  onto  the  cast-iron 
plate.  The  small  material  including  the  dust  is  returned  to 
the  box  with  the  large  coke  each  time  in  order  to  represent  as 
nearly  as  possible,  the  practical  conditions  to  which  coke  is 
subjected. 

After  the  fourth  drop  the  coke  is  screened  on  a  wire  screen 
with  square  holes,  2  inches  in  the  clear. 

The  screen  is  held  horizontally  and  is  shaken  once  after  the 
coke  is  placed  on  it,  but  no  attempt  is  made  to  force  through 
all  the  small  pieces  that  might  go  through  if  they  happened  to 
be  placed  differently  on  the  screen. 

The  coke  is  weighed  carefully  before  being  placed  in  the 
box  the  first  time  and  the  coke  on  the  screen  is  weighed  on 
the  same  scales  after  the  final  screening.  The  coke  is  weighed 
accurately  to  one-eighth  of  a  pound  and  the  result  reported  in 
percentage  of  original  coke  that  does  not  pass  the  screen  after 
the  fourth  drop. 

Determination  of  the  True  Specific  Gravity  of  Coal 
and  Coke  Substance. 

To  determine  the  true  specific  gravity  of  coal  and  coke  sub- 
stance, the  procedure  is  as  follows :  A  sample  of  the  6o-mesh 
coal,  weighing  approximately  3.5  grams  is  dried  at  105°  C., 
and  introduced  into  a  50  cubic  centimeter  pycnometer  with 
about  30  cubic  centimeters  of  distilled  water.  In  order  to 
avoid  loss  of  particles  of  the  sample  during  boiling,  a  one-bulb 
6-inch  drying  tube  (a)  (Fig.  4)  is  connected  with  the  pycnom- 
eter by  means  of  a  small  piece  of  pure  gum  tubing  (c).  The 
other  end  of  the  drying  tube  is  connected  \vith  the  aspirator. 


39 


Suction  is  applied  and  the  contents  of  the  flask  are  gently 
boiled  on  the  water  bath  (d)  under  partial  vacuum  for  3  hours 
in  order  to  expel  all  air  from  the  sample.  The  pycnometer  is 


FIG.  4. 


then  detached,  almost  filled  with  boiled  and  cooled  water,  al- 
lowed to  cool  to  the  temperature  of  the  balance  room,  stop- 
pered, and  weighed.  The  temperature  of  the  contents  of  the 


40 

pycnometer  is  taken  immediately  after  weighing.  Each  pyc- 
nometer  is  accurately  calibrated  and  a  table  is  constructed  giv- 
ing its  capacity  in  grams  of  water  at  different  temperatures. 

True  specific  gravity  is  determined  by  use  of  the  following 
formula : 

W 

The  specific  gravity  = 


W  —  (W1  —  P) 
in  which 

W  =  weight  of  coke. 

W  =  weight  of  pycnometer  -f-  coke  +  water  to  fill. 

P    —  weight  of  pycnometer  -j-  water  to  fill. 

Determination  of  the  Apparent  Specific  Gravity. 

The  apparatus  used  for  the  determination  of  the  apparent 
specific  gravity  consists  of  a  galvanized  iron  cylinder  (Fig.  5) 
which  is  filled  with  water  to  the  water  line,  as  indicated  in  the 
figure.  In  the  cylinder  is  immersed  a  hydrometer  made  of 
brass.  On  the  top  of  the  hydrometer  are  two  pans.  The 
upper  one  is  used  for  weights  and  the  lower  one  for  the 
sample.  Below  the  air  buoy  is  a  brass  cage  perforated  with 
many  holes  to  allow  the  air  to  escape  when  the  instrument  is 
immersed.  The  cage  carries  the  sample  when  it  is  weighed 
under  water. 

The  method  of  determining  the  apparent  specific  gravity  is 
as  follows :  Brass  weights  are  placed  on  the  upper  pan  until 
the  hydrometer  sinks  to  a  mark  on  the  stem  between  the  cop- 
per pan  and  the  buoy.  The  total  weight  required  is  recorded. 
The  weights  are  removed,  and  about  500  grams  of  the  sample 
in  lump  form  (about  1^-  to  2-inch  cubes)  are  placed  in  the 
copper  dish.  Brass  weights  are  then  added  until  the  hydrom- 
eter sinks  to  the  mark  on  the  stem.  The  difference  in  the 
weights  used  gives  the  weight  of  the  sample  in  air.  The 
sample  is  then  carefully  transferred  to  the  brass  cage  below 
the  buoy.  The  weights  on  the  upper  pan  are  now  adjusted 
until  the  instrument  again  sinks  to  the  mark  on  the  stem. 
The  weight  required  to  sink  the  hydrometer  to  the  mark  with 
no  sample  on  the  upper  pan  nor  in  the  brass  cage  minus  the 


FIG.  5. 


42 

weight  required  to  sink  it  to  the  mark  with  the  sample  im- 
mersed in  the  cage  equals  the  weight  of  the  coke  in  water. 
Then 

If  the  weight  of  the  sample  in  air  =  x 

and  the  weight  of  the  sample  in  water  —  y 

"1C 

The  apparent  specific  gravity      -— 

x        y 

Apparent  specific  gravity 

And  100  X  — —  — ^ —  -  =  percentage  bv  volume 

true  specinc  gravity  .  . 

of  coke  substance. 

Also  100  percentage  by  volume  of  coke  substance  =  per- 
centage by  volume  of  cell  space. 

In  making  apparent  specific  determinations  of  coke  the  sam- 
ple should  preferably  be  in  lumps  of  nearly  the  same  size  and 
shape.  When  the  sample  is  immersed,  the  hydrometer  should 
be  moved  rapidly  up  and  down  in  the  water  a  number  of  times 
in  order  to  remove  air  bubbles.  Since  coke  samples  are  porous 
they  take  up  water  rapidly  and  should  not  be  allowed  to  re- 
main in  contact  with  water  more  than  5  minutes  during  a  deter- 
mination. By  observing  the  above-mentioned  precautions  satis- 
factory results  can  be  obtained.  All  samples  should  be  thor- 
oughly dry  before  specinc  gravity  determinations  are  made. 
Ash  Analysis. 

For  ash  analysis  follow  the  method  outlined  under  refrac- 
tories. 

GAS  OIL. 

The  following  determinations  are  covered  in  the  analysis  of 
gas  oil : 

Asphalt.  Index  of  Refraction. 

Bromine  Number.  Mean  Boiling  Point. 

Cold  Test.  Mean  Molecular  Weight. 

Distillation.  Paraffin. 

Flash  Point.  Specinc  Gravity. 

Fire  Point.  Specinc  Heat. 

Heating  Value.  Sulphur. 

Heat  of  Vaporization.  Water. 


43 

It  is  not  recommended  that  all  are  necessary  for  routine 
analysis,  but  special  circumstances  may  require  more  extended 
investigation  as  a  means  of  identifying  the  source  of  an  un- 
known sample  when  such  determinations  may  be  of  great  value. 

There  are  a  number  of  methods  in  the  literature  .that  may 
be  used  for  the  empirical  determination  of  the  relative  propor- 
tion of  the  various  classes  or  groups  of  hydrocarbons  in  gas 
oils.  These  methods,  however,  have  not  had  the  extensive 
use  and  acceptance  that  would  seem  necessary  for  their  incor- 
poration in  the  Handbook  at  this  time. 

Asphalt. 

The  determination  of  asphalt  is  still  in  an  unsatisfactory 
state  as  there  are  a  number  of  precipitants  used  for  the  pur- 
pose, viz.,  petroleum  ether,  alcohol,  ether,  amyl  alcohol,  ethyl 
acetate,  butanon.  The  asphalts  thus  obtained  vary  quite  wide- 
ly both  as  to  quantity  and  hardness  and  there  does  not  seem  to 
be  any  well  denned  relation  existing  between  the  results  ob- 
tained with  the  different  precipitants  on  different  samples  of 
oil. 

The  more  generally  recognized  precipitant  is  naphtha,  and 
the  method  according  to  Engler,  is  as  follows : 

QUANTITATIVE  DETERMINATION. 

Asphalt  Insoluble  in  Naphtha. — Five  grams  of  oil  are  shaken 
in  a  500  cubic  centimeter  bottle  with  40  times  its  volume  (220 
cubic  centimeters,  assuming  the  specific  gravity  to  be  0.9)  of 
normal  benzene.  If  the  oil  contains  only  a  little  asphalt,  as 
much  as  20  grams  of  oil  may  be  taken  with  the  corresponding 
amount  of  naphtha.  After  standing  at  least  24  hours  at  a 
temperature  between  15°  and  20°  and  away  from  direct  sun- 
light, the  solution  is  decanted  through  two  filters  folded  to- 
gether (white  ribbon  S.  &  S.).  The  residue  is  washed  with 
naphtha  till  the  filtrate  gives  no  more  oily  residue.  To  prevent 
the  asphalt  from  becoming  insoluble  on  standing,  it  is  at  once 
dissolved  in  hot  benzol,  the  main  mass  evaporated  from  a 
flask  and  the  remainder  in  a  tared  vessel,  the  residue  dried  at 


44 

IO5°  and  weighed.  Foreign  substances  precipitated  by  naph- 
tha and  insoluble  in  benzol  can  be  separately  determined  by 
using  a  weighed  filter  paper.  If  the  suspended  asphalt  is  to  be 
determined,  the  amount  of  asphalt  is  determined  in  the  original 
oil  as  well  as  in  the  filtered  oil;  the  difference  gives  the  sus- 
pended asphalt.  In  the  different  crude  oils  the  amount  of  as- 
phalt runs  parallel  to  the  amount  of  coke  obtained  on  distilla- 
tion. 

The  German  specifications  for  the  naphtha  require  a  gravity 
at  15°  C.  of  0.695-0.705,  boiling  range  65°  €.-95°  C.  with  100 
cubic  centimeters  using  a  3-bulb  Le  Bel  Henninger  Column  40 
centimeters  long.  Not  over  2  per  cent,  should  dissolve  in  a 
mixture  of  20  per  cent,  fuming  and  80  per  cent.  1.84  H2SO4, 
using  equal  volumes  and  shaking  for  15  minutes. 

Bromine  Number. 

From  0.3  to  0.5  gram  of  oil  is  weighed  into  a  glass  stoppered 
8-ounce  bottle.  Ten  cubic  centimeters  of  bromine  solution  is 
run  from  the  burette,  the  bottle  is  then  cooled  in  ice  water  and 
25  cubic  centimeters  of  10  per  cent,  potassium  iodide  solution 
is  added  shaking  the  bottle,  but  preventing  any  of  the  solution 
from  getting  on  or  near  the  stopper.  Add  I  or  2  cubic  centi- 
meters of  starch  solution  and  titrate  against  standard  sodium 
thiosulphate  solution.  The  reaction  is  as  follows : 

Br2  +  2KI  =  2KBr  +  L, 
I2  +  2Na2S2O3  =  2NaI  +  Na2S4O6. 

Calculation. — Cubic  centimeters  of  bromine  used  x  equiva- 
lent to  thiosulphate  solution  =  equivalent  volume  of  thiosul- 
phate. 

Equivalent  volume  of  thiosulphate  —  thiosulphate  added  in 
titration  =  cubic  centimeters  of  thiosulphate  used. 

Cubic  centimeters  of  thiosulphate  used  x  0.008  =  grams  of 

Grams  of  bromine  absorbed   X    100 
bromine  absorbed.  _.          — - — — - 

Grams  of  oil  used 

bromine  number. 

Solutions. — The  thiosulphate  solution  is  made  up  to  contain 


45 

24.8  grams  of  C.  P.  sodium  thiosulphate  (Na2S2O35H2O)  per 
liter. 

The  bromine  solution  is  made  up  with  dry  carbon  tetra- 
chloride  and  standardized  with  the  thiosulphate.  One  cubic 
centimeter  of  the  bromine  solution  should  equal  approximately 
1.5  cubic  centimeters  of  thiosulphate  solution. 

Distillation. 

The  apparatus  shall  consist  of  the  following  standard  parts : 
(i)     FLASK. 

The  distillation  flask  shall  be  a  standard  100  cubic  centi- 
meter Engler  distilling  bulb  having  the  following  dimensions 
(see  Stillman's  "Engineering  Chemistry"). 

Diameter  of  bulb  6.5  cm. 

Length  of  neck  15.0  cm. 

Diameter  of  neck    1.6  cm. 

Surface  of  oil  to  tubulure 9.0  cm. 

Length  of  tubulure   10.0  cm. 

Angle  of  tubulure   75° 

A  3  per  cent,  variation  from  the  above  measurements  will 
be  allowed. 

(2)     THERMOMETER. 

High  temperature  nitrogen-filled  Fahrenheit  thermometer 
constructed  according  to  the  following  specifications : 

(1)  To  be  made  of  special  German  hardened  glass. 

(2)  Diameter  of   stem  not  less  than  6.75  millimeters  nor 
more  than  7.25  millimeters. 

(3)  Length  of  thermometer  not  less  than  335  millimeters 
nor  more  than  350  millimeters. 

(4)  Length  of  thermometer  between  o°  mark  and  1,000° 
mark  not  less  than  285  millimeters  nor  more  than  300  milli- 
meters. 

(5)  Length  of  bulb  to  capillary  not  less  than  20  millimeters 
nor  more  than  22  millimeters. 

(6)  Diameter  of  bulb  at  center  of  same  not  less  than  5.25 
millimeters  nor  more  than  6.25  millimeters. 

4 


46 

(7)  Mercury  column  to  rise  from  60°  to  200°  in  not  more 
than  5  nor  less  than  3  seconds  when  plunged  into  boiling  water. 

(8)  To  be  correct  within  i°  at  212°  and  750°  after  25  suc- 
cessive oil  tests. 

(3)     CONDENSER. 
Liebig  glass  condenser  and  tube  as  follows : 

Length  of  body  of  jacket 300-350  mm. 

Width  of  body  of  jacket 25-  40  mm. 

Length  of  inner  tube 530  mm. 

Width  of  inner  tube 12-  15  mm. 

Width  of  end  of  inner  tube 20-  25  mm. 

(4)     STANDS. 

Two  iron  stands  provided  respectively  with  one  universal 
clamp  for  holding  condenser,  and  one  light  grip  arm  asbestos 
lined  clamp  for  holding  the  bulb. 

(5)     BURNER  AND  SHIELD. 

Bunsen  burner  with  tin  shield  8  inches  long  by  3  inches  in 
diameter.  The  shield  has  a  sight  hole  in  the  same  for  observ- 
ing the  flame. 

(6)     CYLINDERS. 

Ten  glass  cylinders,  25  cubic  centimeters  capacity,  gradu- 
ated to  i/io  cubic  centimeter. 

SETTING  UP  APPARATUS. 

The  apparatus  is  set  up  as  shown  in  Fig.  6,  the  thermometer 
being  so  placed  that  the  top  of  the  bulb  is  opposite  the  middle 
of  the  tubulure.  All  connections  should  be  tight. 

Distillation  Test. 

One  hundred  cubic  centimeters  of  the  oil  to  be  tested  are 
placed  in  a  weighed  bulb,  and  after  adjusting  the  thermom- 
eter, shield,  condenser,  etc.,  the  distillation  is  commenced,  the 
rate  being  so  regulated  that  I  cubic  centimeter  passes  over 
every  minute.  Cold  water  should  be  passing  through  the  con- 
denser during  the  first  half  of  the  distillation.  When  the 


47 


thermometer  reaches  600°  F.,  the  cold  water  should  be  re- 
moved from  the  condenser  and  hot  water  substituted.  The 
receiver  is  changed  as  the  mercury  column  just  passes  the 
fractionating  point.  At  the  end  of  the  distillation,  or  when  no 
more  oil  distils  over,  the  flask  is  disconnected  from  the  con- 
denser, inverted  and  two  burners  are  used  to  complete  the 
coking. 


FIG.  6. 


The  fractionating  points  in  the  distillation  are  at  every  50° 
F.,  i.  e.,  at  300°,  350°,  400°  F.,  etc.  The  number  of  cubic 
centimeters  obtained  between  each  cutting  point  will  give  the 
per  cent,  by  volume  distilling  between  these  temperatures. 


48 

The  per  cent,  by  weight  is  obtained  as  follows :  Multiply  the 
per  cent,  by  volume  of  each  fraction  by  its  specific  gravity  and 
divide  by  the  specific  gravity  of  the  original  oil. 

In  case  the  oil  contains  more  than  2  per  cent,  of  water,  it 
should  be  dried  by  the  following  method  before  carrying  out 
the  distillation:  A  definite  volume  of  oil  is  placed  in  a  copper 
still  and  heat  gradually  applied  until  all  water  has  distilled 
over,  returning  any  oil  to  the  still  that  has  been  carried  over 
with  the  water. 

For  more  accurate  work  the  emergent  stem  correction  should 
be  applied  to  the  observed  temperature. 

This  has  been  determined  by  the  Bureau  of  Standards  to  be 
approximately  as  follows  for  a  thermometer  in  the  position  as 
used  in  the  distillation  test : 

200°  C 4.50°  C. 

250°  C 6.0°  C. 

300°  C 10.5°  C. 

350°  C 15.5°  C. 

Flash  and  Fire  Tests. 

DIRECTIONS  FOR  OPERATING  TAGUABUE  OPEN  CUP. 
General  Directions. 

1.  Test  shall  be  made  in  a  room  partially  darkened. 

2.  The  cup  shall  be  protected  by  a  surrounding  screen,  16 
inches   square,   30  inches  high,   open  at  top  and   front,   and 
painted  black  inside.    Drafts  caused  by  the  breath  of  the  oper- 
ator shall  be  carefully  avoided. 

3.  A  fresh  sample  shall  be  used  for  each  test. 

4.  The  instrument  must  stand  level. 

Preparation  of  Water  Bath. — Fill  the  metal  bath  with  water 
at  a  temperature  of  25°  C.  (77°  F.)  so  that  when  the  glass  cup 
is  in  place,  the  water  in  bath  will  come  to  the  rim  of  the  metal 
cup. 

Preparation  of  Sample. — Suspend  a  calibrated  thermometer 
(see  specifications)  in  the  center  of  the  cup  with  the  top  of 
the  bulb  of  same  y2  inch  below  the  upper  level  edge  of  the 


49 

glass  cup.  Bring  sample  to  be  tested  to  a  temperature  of 
15.5°  C.  (60°  F.).  Fill  the  glass  cup  with  59  cubic  centimeters 
of  the  sample.  See  that  there  is  no  oil  on  the  outside  of  the 
cup  or  its  upper  edge,  using  a  filter  paper  to  clean  the  cup. 
Remove  air  bubbles,  if  any,  from  the  surface  of  the  oil. 

NOTE. — The  horizontal  flashing-taper  guide  wire  (as  speci- 
fied by  direction  of  the  manufacturer)  Is  not  to  be  used  In  these 
tests. 

Application  of  Heat  to  Oil  Cup. — Heat  the  bath  with  an 
alcohol,  gas  or  other  flame,  so  adjusted  that  the  temperature 
will  not  be  raised  faster  or  much  slower  than  i°  C.  (1.8°  F.) 
per  minute,  without  removing  the  flame. 

Description  of  Test  Flame. — The  test  flame  shall  be  spher- 
ical in  form,  and  shall  have  a  diameter  equal  in  size  to  the  bead 
furnished  herewith,  which  may  be  attached  to  the  cover  of  the 
water  bath.  This  flame  is  best  produced  by  passing  gas 
through  a  straight  thin  metal  blow-pipe  tube.  (See  Eimer  and 
Amend  Catalogue  C  (1913,  p.  54,  Item  784)  or  Scientific  Ma- 
terials Co.  (1912,  p.  69,  Item  618)  or  C.  J.  Tagliabue  special 
tube. 

Initial  Test. — When  the  sample  under  test  reaches  a  temper- 
ature of  30°  C.  (86°  F.)  the  first  test  shall  be  made,  and  tests 
shall  be  made  thereafter  at  each  rise  of  i°  C.  (1.8°  F.)  until 
the  flash  point  is  reached. 

Method  of  Applying  Test  Flame. 
(Two  Methods,  both  to  be  used  and  reported.) 

(A)  Sweep  Method. — Holding  the  burner  tube  in  a  truly 
horizontal  position  the  flame  is  passed  in  a  straight  line  con- 
tinuously across  the  center  of  the  cup,  with  the  tube  touching 
the  edge  of  the  cup.     The  time  for  one  sweep  from  edge  to 
edge  of  the  cup  to  be  gauged  to  I  second.     The  temperature 
at  which  a  flame  first  appears  anywhere  on  the  surface  of  the 
oil  shall  be  considered  the  flash  point. 

(B)  Dip  Method. — Holding  the  burner  tube  in  a  vertical 
position  with  the  flame  3   inches  above  the  surface  of  the 
sample,  the  flame  is  quickly  lowered  to  Y%  inch  from  the  sur- 


50 

face  of  the  sample  near  the  outer  edge  of  the  cup,  and  with- 
drawn; entire  operation  consuming  one  second.  This  opera- 
tion is  quickly  repeated  at  three  equidistant  points  around  the 
circumference  of  the  cup.  The  temperature  at  which  a  blue 
flame  jumps  from  the  taper  to  the  surface  of  the  oil  is  the 
flash  point. 

DIRECTION  FOR  OPERATING  THE  EUJOTT  OR  N.  Y.  STATE  TESTER. 
General  Directions. 

1.  Test  shall  be  made  in  a  room  partially  darkened. 

2.  The  cup  shall  be  protected  by  a  surrounding  screen,  16 
inches   square,   30  inches  high,  open  at  top  and   front,   and 
painted  black  inside.    Drafts  caused  by  the  breath  of  the  oper- 
ator shall  be  carefully  avoided. 

3.  A  fresh  sample  shall  be  used  for  each  test. 

4.  The  instrument  must  stand  level. 

Preparation  of  Water  Bath. — Fill  the  metal  bath  with  water 
at  a  temperature  of  25°  C.  (77°  F.)  so  that  when  the  metal 
cup  is  in  place,  the  water  in  bath  will  come  to  the  rim  of  the 
metal  bath. 

Preparation  of  Sample. — Bring  the  sample  to  be  tested  to  a 
temperature  of  15.5°  C.  (60°  F.).  Fill  the  metal  cup  with 
the  sample  to  such  a  point  that  the  surface  of  the  oil  will  be 
1/8  inch  below  the  lower  inner  flange.  Remove  air  bubbles,  if 
any,  from  the  surface  of  the  sample.  Place  the  glass  cover  in 
position  and  insert  the  calibrated  thermometer  (see  specifica- 
tions) through  the  cork  in  the  central  opening  so  that  the  top 
of  the  bulb  will  be  %  inch  below  the  surface  of  the  sample. 

Application  of  Heat  to  Oil  Cup. — Heat  the  bath  with  an  al- 
cohol, gas  or  other  flame,  so  that  the  temperature  will  not  be 
raised  faster  or  much  slower  than  i°  C.  (1.8°  F.)  per  min- 
ute, without  removing  the  flame. 

Description  of  Test  Flame. — The  test  flame  shall  be  spheric- 
al in  form,  and  shall  have  a  diameter  equal  in  size  to  the 
bead  furnished  herewith,  which  may  be  attached  to  the  cover 
of  the  water  bath.  This  flame  is  best  produced  by  passing  gas 


through  a  straight  thin  metal  blow-pipe  tube.  (See  Eimer  and 
Amend  Catalogue  C  (1913,  p.  54,  Item  704)  or  Scientific  Ma- 
terials Co.  (1912,  p.  69,  Item  618)  or  C.  J.  Tagliabue  special 
tube. 

Initial  Test. — When  the  sample  under  test  reaches  a  temper- 
ature of  25°  C.  (77°  F.)  the  first  test  shall  be  made.  Tests 
shall  be  made  thereafter  at  each  rise  of  i°  C.  (1.8°  F.)  until 
the  flash  point  is  reached. 

Method  of  Applying  Test  Flame. — Holding  the  burner  tube 
at  an  angle  of  45°,  the  flame  is  passed  through  the  side  open- 
ing in  the  cover  to  a  point  half  way  between  the  surface  of 
the  sample  and  the  cover.  The  time  consumed  in  entering 
and  withdrawing  the  flame  is  to  be  I  second.  The  tempera- 
ture at  which  a  blue  flame  is  seen  through  the  glass  is  the 
flash  point. 

Specification  for  Thermometer  for  Flash  Point  Tests. 
To  be  used  with  Tagliabue  and  Elliott  or  N.  Y.  State  Testers. 

The  thermometer  shall  be  graduated  from  — 10°  to  rj-iio° 
C.  in  i°  intervals.  There  shall  be  a  small  reservoir  above  the 
110°  mark.  The  thermometer  shall  be  finished  at  the  top  with 
a  small  glass  ring. 

The  stem  shall  be  made  of  enamel  backed  thermometer  tub- 
ing, but  not  of  Jena  I6111  glass.  The  bulb  shall  be  made  of 
Jena  I6111,  Corning  normal,  or  Jena  or  Corning  borosilicate 
glass. 

Every  fifth  graduation  shall  be  longer  than  the  intermediate 
ones  and  the  marks  shall  be  numbered  at  every  10°  interval. 
The  graduation  marks  shall  be  clear  cut  and  fine,  and  the  num- 
bering clear  and  distinct. 

Each  thermometer  shall  be  provided  with  a  suitable  case. 
A  serial  number  for  identification  shall  be  engraved  on  the 
stem. 

All  material  and  workmanship  shall  be  of  the  bes,t  grade. 

Accuracy. — The  maximum  error  at  any  point  shall  not  ex- 
ceed three-tenths  (0.3)  degree  Centigrade. 


52 

Dimensions : 

Total  length,  not  over  300  millimeters. 

Diameter  stem,  from  5.5  to  7  millimeters. 

Diameter  bulb,  same  as  stem. 

Diameter  capillary,  not  less  than  o.i  millimeter. 

L,ength  of  bulb,  from  8  to  12  millimeters. 

Distance — 10°  to  bottom  of  bulb,  from  40  to  60  milli- 
meters. 

Distance — 10°  to  no0  on  scale,  from  180  to  220  milli- 
meters. 

Heating  Value. 
Refer  to  Heating  Value  of  coal  analysis  on  page  30. 

Heat  of  Vaporisation. 

The  heat  of  vaporization  may  be  calculated  with  sufficient 
accuracy  for  purpose  of  design  from  the  mean  molecular 
weight  and  the  mean  boiling  point  and  specific  heat  from 
Trouton's  rule. 

Mean  boiling  point 

(Heat  of  vaporization)  =  20.      — — • — ;!    . 

Mean  Molecular  Weight 

The  total  heat  of  vaporization  —  sensible  heat  from  room 
temperature  to  boiling  point  +  latent  heat  of  vaporization  so 
there  must  be  added  (mean  boiling  point  —  room  temperature) 
(specific  heat). 

Refractive  Index. 

The  Zeiss  refractometer  is  recommended  for  the  refractive 
index  at  a  temperature  of  25°  C.,  at  which  point  all  fractions 
of  the  usual  gas  oils  are  sufficiently  liquid  for  observation.  As 
detailed  instructions  are  furnished  with  the  instrument  they 
are  not  repeated  here. 

The  use  of  the  refractive  index  instead  of  the  specific  grav- 
ities for  the  fractions  of  gas  oils  is  recommended  as  giving 
really  more  information  and  requiring  but  a  fraction  of  the 
time  to  determine. 


53 

Mean  Boiling  Point. 

This  figure  is  the  arithmetical  mean  of  the  temperature  at 
which  equal  volumes  of  the  oil  distil  off. 

The  oil  is  distilled  in  the  usual  form  of  apparatus  and  the 
temperatures  noted  when  the  first  drop,  10  per  cent.,  20  per 
cent.,  30  per  cent.,  etc.  have  distilled  over.  The  sum  is  divided 
by  the  number  of  fractions.  The  mean  boiling  point  is  ex- 
pressed in  absolute  temperature  for  use  in  calculating  the  heat 
of  vaporization. 

Mean  Molecular  Weight. 

This  figure  is  frequently  quite  useful  for  identification  pur- 
poses and  for  use  in  calculating  the  heat  of  vaporization.  The 
determination  is  made  in  a  Beckman  freezing  point  apparatus. 
Commercial  stearic  acid  previously  standardized  with  a  sub- 
stance of  known  molecular  weight  or  benzol  may  be  used  as 
solvents.  The  operation  is  as  follows  : 

The  freezing  tube  A,  with  the  stirrer  and  garnets,  is  care- 
fully washed  and  dried,  and  from  15  to  20  grams  of  the  sol- 
vent accurately  weighed  into  it.  It  is  stoppered  both  at  the 
top  and  side  tube  and  placed  in  the  jacket  tube  B.  The  jar  C 
is  then  filled  with  a^freezing  mixture  (for  benzol,  water  with 
a  small  piece  of  ice  is  suitable). 

The  Beckman  thermometer  is  adjusted  so  that  the  mercury 
at  the  freezing  point  of  the  solvent  (benzol  =  5°  C.)  is  some- 
what above  the  middle  point  of  the  scale.  The  thermometer 
is  inserted  in  the  perforated  stopper  holding  the  platinum 
stirrer  and  after  dropping  in  a  few  small  garnets  the  ther- 
mometer and  stirrer  are  rapidly  inserted  in  place  of  the  stop- 
per in  the  freezing  tube.  By  this  time  the  solvent  should  be 
from  i°  to  2°  below  the  freezing  point.  The  stirrer  is  worked 
up  and  down  to  cause  the  formation  of  crystals — as  these  be- 
gin to  form  the  thermometer  rises  and  as  it  reaches  the  freez- 
ing point  remains  practically  stationary  (vibrating  a  few 
thousandths  under  the  magnifying  glass  however)  the  mean 
point  is  observed.  The  freezing  mixture  should  be  stirred  con- 


54 


stantly  and  the  solvent  should  be  stirred  at  a  uniform  rate  of 
from  30  to  35  strokes  per  minute. 


FIG.    7. 


The  freezing  tube  is  removed  and  from  0.5  to  0.7  gram  of 
the  substance  is  brought  into  the  solvent  through  the  side  tube. 
For  oils  a  weighing  pipette  is  useful,  as  the  quantity  must  be 


55 

i 

accurately  weighed  out.  Care  must  be  taken  to  allow  the  tem- 
perature to  rise  until  all  crystals  have  disappeared  but  not 
far  enough  to  destroy  the  setting  of  the  thermometer.  The 
freezing  tube  is  replaced  and  when  the  substance  has  gone  into 
solution  the  freezing  point  is  observed  as  before.  The  differ- 
ence is  the  depression  (t).  Repeated  additions  of  the  solvent 
may  be  made  and  the  depressions  noted.  The  depression  (t) 
should  not  be  less  than  0.5°  and  not  over  3.0°. 
If  M  =  molecular  weight  of  substance. 

C  =  constant  of  solvent. 

P  —  grams  of  substance  per  100  grams  of  solvent. 

t  =  depression  of  freezing  point. 

M       CP 

M  = 

t 

The  solvent  should  be  standardized  with  a  pure  substance  of 
known  molecular  weight  (naphthalene  may  be  used  with  ben- 
zol). If  20  grams  of  benzol  were  used  and  0.5  gram  naph- 
thalene added,  producing  a  depression  of  0.986°  we  would  have 

M  t        128  X  0.986 

Constant  =  -=—  ='—  -  =  so. 48 

P  0.5  X   IOQ 

20 

Then  assuming  19  grams  of  benzol  used,  0.7  gram  of  oil  added 
and  t  =  1.195  we  would  have 

cp  (o  7  X  IPO ) 

M  =    —    =  50.48  X 19         =  =  155 

i  195 

REFERENCES.— Z.  phys.  Ch.,  i,  pp.  577,  631;  2,  pp.  307,  491,  638,  964; 
5,  p.  94;  B.,  21,  pp.  711,  860;  22,  pp.  1430,  2501;  23,  R  i;  24,  pp. 
1431 ;  27,  R  542,  R  845,  R  974. 

Paraffine. — One  hundred  grams  of  crude  oil  are  distilled 
rapidly  from  a  tubulated  retort  till  the  temperature  of  300°  is 
reached.  A  weighed  receiver  is  then  put  into  position  (with- 
out a  condenser)  and  all  oil  driven  over  until  the  residue  cokes 
completely  (without  thermometer)  ;  the  amount  of  heavy  oil 
distilled  is  determined. 

Five-tenths  gram  of  the  substance  is  dissolved  at  room  tern- 


56 

perature  in  a  mixture  of  ether  and  absolute  alcohol  (i  :  i)  to 
a  clear  solution,  then  cooling  to  — 20°,  just  enough  alcohol- 
ether  mixture  added  till  all  oily  drops  are  dissolved  and  par- 
affine flakes  are  visible.  With  much  paraffine,  it  is  advisable 
to  warm  with  ether  to  complete  solution  and  then  add  the 
same  volume  of  alcohol.  The  precipitated  paraffine  is  then  fil- 
tered on  a  funnel  surrounded  with  a  rock-salt  and  ice-freez- 
ing mixture,  all  traces  of  the  alcohol-ether  solution  being  re- 
moved, and  then  washed  free  from  oil  by  means  of  cooled 
alcohol-ether.  The  residue  is  then  washed  into  a  weighed 
glass  dish  with  hot  benzol,  or  naphtha  and  the  solvent  evap- 
orated on  a  water  bath. 

The  paraffine  is  carefully  washed  with  cooled  alcohol-ether 
until  5  cubic  centimeters  of  the  filtrate  on  evaporation  will 
give  no  residue,  or  only  a  trace  of  material  solid  at  room  tem- 
perature, is  obtained;  too  prolonged  washing  is  to  be  avoided 
because  of  the  still  quite  noticeable  solubility  of  paraffine  in 
alcohol-ether.  If  on  cooling,  the  paraffine  is  seen  to  be  hard, 
it  is  heated  at  105°  for  15  minutes  and  weighed  after  drying 
in  a  desiccator;  if  the  paraffine  is  soft  (with  melting  point 
under  45°),  it  should  be  dried  several  hours  in  a  vacuum 
desiccator  at  50°  before  weighing. 

Determination  of  Specific  Gravity. 

For  control  tests  on  the  original  sample,  the  specific  gravity 
may  be  taken  with  sufficient  accuracy  with  a  hydrometer. 

The  oil  should  either  be  brought  to  the  normal  temperature 
15.5°  C.  or  25°  C.,  or  else  the  temperature  observed  and  the 
gravity  corrected  back  to  normal  temperature. 

Specific  gravity  at  T  =  observed  gravity  at  temperature 
t°  +  (T  —  t  x  0.009). 

In  determining  the  specific  gravity  of  the  fractions  the 
Sprengel  tube  type  of  pycnometer  is  recommended.  The  tube 
is  completely  filled  and  is  immersed  in  water  at  the  normal 
temperature  for  15  minutes.  The  tube  is  tilted  and  the  excess 
material  remove^!  from  the  capillary  with  filter  paper  until  the 


57 

liquid  reaches  the  calibrated  mark.  The  tube  is  then  dried  and 
weighed. 

Platinum  or  nickel  wire  should  be  used  in  suspending  the 
tube  on  the  balance. 

For  a  calibration  of  the  tube  made  by  weighing  empty  and 
filled  with  water  at  the  normal  temperature  the  specific  gravity 
is  given  by  the  formula : 

Weight  filled  with  oil  =  weight  empty 

Specific  gravity  .        .       , — — — ^-r— 

Weight  filled  with  water  =  weight  empty 

While  the  former  practice  has  been  to  determine  specific 
gravity  at  15.5°  C.,  the  later  standards  of  the  American  Society 
for  Testing  Materials  have  very  generally  used  25°  C.  as  the 
normal  temperature,  and  the  use  of  this  temperature  is  recom- 
mended. 

Specific  Heat. 

This  determination  is  made  with  a  Parr  or  bomb  calorim- 
eter, using  the  oil  instead  of  water  as  a  calorimeter  liquid, 
and  burning  a  definite  quantity  of  a  pure  substance  such  as 
sugar  or  benzoic  acid.  Owing  to  the  low  specific  heat  of  the 
oil,  the  quantity  to  be  burned  should  be  roughly  calculated, 
using  0.45  as  an  assumed  specific  heat  of  the  oil  to  secure  a 
temperate  rise  of  not  over  2.5°. 

The  operation  is  carried  on  exactly  as  described  for  deter- 
mining the  heating  value : 

(Grams  substance  X  heating  value)  =  ( Water  equivalent  X  corrected  rise \ 
( Weight  of  oil  taken)  X  (Corrected  rise) 

Sulphur. 

This  determination  is  most  conveniently  carried  out  together 
with  the  determination  of  the  heating  value  in  the  bomb  calo- 
rimeter. After  the  combustion  the  gases  are  allowed  to  escape 
slowly  through  a  10  per  cent,  solution  of  sodium  carbonate 
using  about  20-25  cubic  centimeters  in  a  small  beaker  or  test 
tube. 

The  bomb  is  then  washed  out  thoroughly  with  water,  the 
soda  solution  is  added  to  the  washing  and  the  solution  boiled 
until  the  aluminum  and  iron  are  precipitated,  filtered  and 


58 

washed.  The  solution  should  have  a  volume  of  70-100  cubic 
centimeters — is  accelerated  with  HC1  and  precipitated  in  a 
boiling  solution  with  BaClg. 

BaSO4x  0.1373  =  S. 

A  METHOD  BY  ROTHE. 

Three-fourths  gram  of  oil  with  1.5  grams  of  MgO  and  30- 
40  cubic  centimeters  of  nitric  acid  (specific  gravity  1.48)  are 
placed  in  a  250  cubic  centimeter  round  bottom  Jena  flask. 
Hood.  After  the  first  violent  reaction,  the  flask  is  heated 
gently  for  iJ^-2  hours  in  a  sand  bath,  the  liquid  being  kept 
boiling  gently.  The  excess  nitric  acid  is  then  evaporated  over 
a  free  flame  and  the  residue  heated  till  the  nitrates  begin  to 
decompose.  After  cooling,  10  cubic  centimeters  concentrated 
acid  are  again  added.  After  15  minutes  heating,  the  mass  is 
evaporated  to  dryness,  keeping  the  flask  in  constant  motion, 
then  heated  with  a  triple  burner  until  the  nitrates  are  com- 
pletely decomposed.  The  residue  is  generally  white ;  by  adding 
10  cubic  centimeters  of  hydrochloric  acid  (specific  gravity 
11.24)  and  heating,  it  is  dissolved  and  then  filtered  after  dilu- 
ting with  20-30  cubic  centimeters  of  water.  In  the  filtrate,  the 
sulphuric  acid  is  determined  by  precipitation  with  barium 
chloride  in  the  customary  manner. 

Water. 

Small  quantities  of  water  may  be  determined  in  the  course 
of  the  distillation  test.  Should  the  water  exceed  2  per  cent, 
it  should  be  determined  separately. 

Water  is  quantitatively  determined  as  follows : 
About  loo  grams  of  oil  (less  if  much  water  is  present)  are 
distilled  from  an  oil  bath  with  toluol;  this  toluol  should  have 
been  previously  saturated  with  water.  Pumice  is  added  to 
avoid  bumping.  Eighty  to  ninety  cubic  centimeters  are  caught 
in  a  cylinder  constricted  to  a  narrow  graduated  tube  at  the 
bottom  ( Hoffman-Mar cusson).  After  washing  the  inside  of 
the  condenser  with  toluol  and  loosening  any  water  drops  on 
the  side  of  the  cylinder  with  a  stirring  rod,  the  amount  of 
water  can  be  directly  read  on  the  graduations. 


59 

TESTING  OF  PURIFICATION  MATERIAL. 

New  Material. 

The  following  determinations  are  covered  in  the  analysis 
of  new  oxide : 

Weight  per  Bushel. 
Sampling. 
Moisture. 
Metallic  Iron. 
Iron  Sesquioxide. 
Fouling  Test. 

Used  Purification  Material. 

The  following  determinations  are  covered  in  the  analysis  of 
used  oxide: 

Sampling. 

Moisture  and  Light  Oils. 

Total  Sulphur. 

Soluble  Sulphur  and  Tarry  Matter. 

New  Purification  Material. 
WEIGHT  PER  BUSHEL  AND  SAMPLING. 

These  two  determinations  can  conveniently  be  done  in  one 
operation.  The  necessary  apparatus  are : 

Bushel  box,  made  of  wood,  the  capacity  to  be  2,150.4  cubic 
inches,  approximate  dimensions  inside  12  x  12  x  15  inches. 

Sampling  tool  made  of  brass  tubing,  2  inches  in  diameter, 
1 8  inches  long,  upper  surface  cut  away  to  a  length  of  about 
15  inches,  and  rounded.  A  wooden  handle  is  attached  to  the 
other  end.  Fig.  8. 


)G 


,2" 

• — ^ 

Section 


FIG.    8. 


Ordinary  garden  trowel. 

The  operations  are  as  f  ollowrs  : 

Samples  are  taken  from  a  number  of  bags  by  thrusting  the 


6o 

sampling  tool  into  each  bag  in  turn.  The  number  of  bags 
sampled  depends  on  the  size  of  the  lot  of  oxide  received.  It 
should  be  at  least  10  per  cent,  of  the  total  number  of  bags. 
For  instance,  if  the  lot  contains  500  bags,  a  sample  should  be 
taken  from  every  tenth  bag,  or  from  50  of  the  bags. 

These  samples  are  then  thrown  together  on  a  clean  surface, 
mixed,  and  spread  out  to  a  depth  of  about  3  inches.  Portions 
are  then  taken  over  the  surface  at  equal  distances  with  the 
garden  trowel,  digging  down  to  the  bottom  when  taking  each 
portion.  These  portions  are  thrown  into  the  bushel  box  and 
well  mixed.  Sufficient  material  is  taken  in  this  manner  to 
fill  the  box  level  with  the  upper  edge.  The  box  and  contents 
are  then  weighed.  The  weight  of  the  empty  box  deducted 
from  this  weight  gives  the  pounds  of  oxide  per  bushel.  The 
contents  of  the  box  are  quartered  down  and  the  sample  finally 
obtained  put  into  a  quart  glass  Mason  jar,  or  a  tin  can  with 
air-tight  cover. 

CAUTION. — If  the  oxide  contains  metallic  iron,  it  must  be 
mixed  as  little  as  possible  consistent  with  obtaining  a  repre- 
sentative sample,  because  the  greater  density  of  the  iron  will 
cause  it  to  pass  to  the  bottom,  thus  interfering  with  the  uni- 
formity of  the  sample. 

If  the  oxide  is  not  shipped  in  bags,  the  operator  must  use  his 
judgment  when  sampling,  bearing  in  mind  that  the  portions 
should  be  taken  throughout  the  shipment  in  a  uniform  manner, 
so  that  the  final  sample  will  be  representative  of  the  entire 
shipment. 

MOISTURE. 

Weigh  out  100  grams  from  the  jar  or  can  into  a  counter- 
poised tin  dish,  on  a  balance  accurate  to  o.i  gram.  Dry  in  an 
oven  at  100°  C.  for  one  hour.  The  loss  of  weight  is  reported 
as  moisture. 

The  dried  sample  is  then  ground  in  a  coffee  mill  until  it  is 
about  3o-mesh  size,  and  quartered  down  until  about  30  grams 
are  finally  obtained.  This  final  sample  is  kept  in  a  tightly 


6i 

stoppered,  wide  mouth  bottle,  and  used  in  subsequent  deter- 
minations. 

Note. — The  grinding  is  best  done  by  first  having  the  mill 
set  to  grind  coarsely,  then  repeating  as  many  times  as  neces- 
sary, adjusting  the  mill  to  grind  finer  each  time.  By  this 
method,  usually,  no  difficulty  will  be  found  in  breaking  down 
any  iron  borings  that  may  be  in  the  oxide. 

METALLIC  IRON. 

Weigh  one  gram  of  the  dried  oxide  from  the  bottle  above 
into  a  100  cubic  centimeter  beaker  and  treat  with  50  cubic 
centimeters  neutral,  saturated  solution  of  cupric  ammonium 
chloride,  allow  to  stand  with  frequent  stirring  for  at  least 
an  hour  in  a  warm  place,  when  all  particles  of  metallic  iron 
should  be  dissolved.  Filter  off  the  residue  and  wash  free  of 
chlorides,  and  to  the  hot  filtrate  add  ammonia  in  excess.  The 
iron  will  be  precipitated  as  hydroxide,  while  the  blue  cupric 
hydrate  dissolves  in  excess.  Filter  off  the  precipitate,  wash 
with  water  containing  a  little  ammonia  until  practically  free 
from  copper  salts. 

Dissolve  the  precipitate  on  the  filter  with  hot,  dilute  hydro- 
chloric acid,  i  in  10,  and  wash  free  from  HC1.  To  the  hot 
filtrate,  ammonia  is  again  added  in  excess  to  precipitate.  The 
precipitate  is  then  filtered,  washed,  and  ignited.  Weigh  as 
Fe2O3.  This  weight  multiplied  by  69.94  gives  the  percentage 
of  metallic  iron  found. 

Note. — This  method  must  be  regarded  as  only  approximate. 
It  is,  however,  the  best  method  the  Committee  has  been  able  to 
find.  It  gives  low  results,  due  to  the  oxidation  of  the  iron 
when  the  residue  is  being  filtered  from  the  cupric  ammonium 
chloride.  The  error  varies  with  the  percentage  of  metallic 
iron  present,  being  greatest  when  this  percentage  is  low. 

If  large  pieces  of  iron  borings  are  present  it  is  advisable  to 

remove  them  with  a  magnet,  brush  off  the  adhering  oxide  of 

iron,  etc.,  returning  the  latter  to  the  sample  to  be  analyzed. 

The  clean  pieces  are  weighed  and  the  percentage  calculated 

5 


62 


and  added  to  the  metallic  iron  found  by  the  method  described 
above. 

IRON  SESQUIOXIDE. 

Iron  is  usually  present  in  an  oxide  in  some  form  of  hydrated 
ferric  oxide.  It  is  not  practicable  to  determine  accurately  the 
state  of  hydration ;  hence,  it  has  been  thought  best  to  determine 
and  report  the  oxidized  iron  present  as  sesquioxide. 

Dissolve  0.5  gram  of  the  dried  sample  in  20  cubic  centime- 
ters (1:1)  hydrochloric  acid  in  a  100  cubic  centimeter  beaker, 
evaporate  to  dryness,  adding  a  few  drops  of  nitric  acid  from 
time  to  time.  Take  up  with  5  cubic  centimeters  concentrated 
hydrochloric  acid,  add  50  cubic  centimeters  hot  water,  boil  and 
filter.  Wash  filter  well  with  hot  water.  To  the  filtrate,  add  25 
cubic  centimeters  bromine,  water  and  heat  to  boiling.  When 
the  excess  of  bromine  has  been  driven  off,  remove  beaker  from 
heat  and  precipitate  the  iron  as  hydroxide  with  ammonia.  Boil 
for  five  minutes;  allow  the  precipitate  to  settle.  Filter,  wash 
well  with  hot  water,  dry,  ignite,  and  weigh  as  Fe2O3.  This 
gives  the  total  iron  in  terms  of  Fe2O3.  If  metallic  iron  is  pres- 
ent, it  must  be  determined  by  the  previous  method,  and  its 
amount  also  in  terms  of  Fe2O3  deducted  from  the  total  iron 
as  Fe2O3.  The  difference  will  be  iron  sesquioxide.  This 
weight  multiplied  by  200  gives  the  per  cent,  of  iron  sesqui- 
oxide. 

Alternate  Method. — The  residue  obtained  from  the  cupric 
ammonium  chloride  solution  in  the  method  for  metallic  iron  is 
ignited  in  a  platinum  crucible  until  all  carbonaceous  matter  is 
destroyed  and  there  remains  only  a  mass  of  red  ferric  oxide. 

Transfer  as  much  as  possible  of  this  to  a  100  cubic  centi- 
meter beaker,  dissolve  in  15  cubic  centimeters  to  30  cubic  centi- 
meters concentrated  hydrochloric  acid,  at  the  same  time  dis- 
solving from  the  crucible  any  adhering  particles  of  ferric  oxide. 
When  solution  is  complete,  filter  into  a  250  cubic  centimeter 
graduated  flask.  Wash  and  ignite  the  residue  in  a  platinum 
crucible,  and  fuse  with  two  grams  of  dry  sodium  carbonate. 
Dissolve  the  fusion  in  hydrochloric  acid,  add  this  to  the  con- 


tents  of  the  250  cubic  centimeter  flask,  fill  to  the  mark  with 
distilled  water,  and  mix  well.  With  a  pipette,  transfer  50 
cubic  centimeters  to  a  150  cubic  centimeter  beaker,  add  am- 
monia to  precipitate  the  ferric  hydroxide,  boil  for  five  minutes, 
allow  to  settle,  and  filter.  Wash  with  hot  water,  dry,  ignite, 
and  weigh  as  Fe2O3.  The  weight  multiplied  by  500  gives  the 
per  cent,  of  iron  sesquioxide. 

FOULING  TEST. 

The  fouling  test  of  an  oxide  offers  the  best  means  for  de- 
termining its  value  for  purification  purposes. 

A  glass  tube  with  a  bulb  at  one  end  is  most  suitable  to  hold 
the  oxide  to  be  tested,  but  a  U-tube  or  almost  any  other  tube 
compact  enough  so  that  it  can  be  weighed  on  analytical  balance 
will  answer.  (See  C  in  Fig.  9.) 


FIG.  9. 


Five  grams  of  the  oxide  to  be  tested  are  next  mixed  with 
about  2  grams  of  coarse  sifted  sawdust  and  placed  in  the  tube, 
and  covered  with  a  layer  of  cotton  to  prevent  any  of  the  con- 
tents from  falling  out  at  the  stopper  end  of  the  tube.  The 
stopper  is  then  inserted.  The  entire  tube  is  accurately  weighed 
and  the  total  weight  noted.  For  sponge  ore  oxide  already 
mixed  with  shavings  the  sawdust  is  omitted.  This  tube  is 
followed  by  a  U-tube  containing  calcium  chloride  and  weighed 


64 

together  with  the  tube  holding  the  oxide.  Another  large  U- 
tube  or  a  tower  filled  with  calcium  chloride  to  dry  the  hydrogen 
sulphide  issuing  from  the  generator  is  connected  with  the  test 
tube  by  means  of  a  piece  of  rubber  tubing  and  the  whole  con- 
nected with  the  generator.  A  small  piece  of  glass  tubing 
closed  at  one  end  so  as  to  leave  only  a  hole  the  size  of  a  small 
pinhole  and  placed  between  the  U-tube  and  the  generator  reg- 
ulates the  flow  of  gas. 

The  hydrogen  sulphide  gas  generated  in  the  Kipp  generator 
A,  and  dried  by  passing  it  through  the  calcium  chloride  in  the 
U-tube  or  tower  B,  is  decomposed  by  the  iron  oxide  in  the 
test-tube  C,  forming  iron  sulphide  and  water.  The  water 
formed  is  absorbed  by  the  calcium  chloride  in  the  second  test- 
tube  D. 

The  test  is  carried  on  for  one  hour,  after  which  time  the  test- 
tubes  are  disconnected  and  weighed.  The  gain  in  weight  repre- 
sents the  amount  of  hydrogen  sulphide  absorbed,  or  rather 
decomposed,  by  the  oxide.  By  dividing  the  amount  of  oxide 
taken  into  this  weight,  the  percentage  of  hydrogen  sulphide 
decomposed  can  be  determined,  and  from  the  latter  the  sulphur 
calculated. 

Some  oxides  are  very  active  at  the  first  fouling  (when  new), 
but  revivification  is  slow  and  incomplete,  and  on  second  fouling 
they  give  far  lower  results.  For  this  reason  it  is  sometimes 
desirable  to  carry  the  test  far  enough  to  determine  the  total 
absorbing  capacity  of  an  oxide. 

After  the  first  fouling,  the  oxide  tube  is  disconnected  from 
the  CaCl2  tube,  and  air  passed  over  it  until  completely  revivi- 
fied. To  prevent  an  oxide  which  has  the  tendency  to  revivify 
very  rapidly  from  getting  too  hot  and  consequently  burning, 
thus  becoming  more  or  less  inert,  it  is  advisable  to  pass  the 
air  used  for  revivification  over  water  so  as  to  saturate  it  with 
water  vapor.  For  this  reason  it  is  not  advisable  to  remove  the 
oxide  from  the  tube  for  revivification,  for  it  being  very  dry,  on 
direct  exposure  to  air,  any  very  active  oxide  is  found  to  take 
fire. 

After  complete  revivification,  the  tubes  of  oxide  and  CaCl2 


65 

are  again  weighed  and  connected  with  the  Kipp  apparatus,  and 
fouled  a  second  time.  This  second  fouling  as  a  rule  is  suffi- 
cient to  show  how  active  the  material  is,  for  if  the  results  of 
the  second  fouling  are  very  close  to  those  of  the  first,  the 
material  is  very  active,  but  the  test  can  be  repeated  the  same 
number  of  times  as  the  oxide  is  revivified  in  practice.  Thus 
the  entire  capacity  of  the  oxide  can  be  determined  before  it  is 
placed  in  service. 

\ 
Used  Purification  Material. 

SAMPLING. 

Used  purification  material  may  be  required  to  be  sampled 
under  two  conditions. 

I.  When  removed  from  the  box  for  revivification. 

II.  When  revivified  in  the  box. 

When  the  oxide  has  been  removed  from  the  box  and  spread 
out,  portions  may  be  taken  to  the  entire  depth  of  the  bed  with 
the  trowel  at  points  situated  at  equal  distances  over  the  sur- 
face. When  about  a  bushel  has  been  obtained,  this  is  thor- 
oughly mixed,  quartered  down,  and  a  quart  jar  or  can  filled 
and  tightly  closed. 

When  the  oxide  is  revivified  in  silu,  samples  should  be  taken 
in  different  parts  of  the  box,  the  operator  using  his  judgment 
and  endeavoring  to  obtain  a  sample  which  represents  the  entire 
contents  of  the  box. 

MOISTURE  AND  UGHT  OILS. 

Weigh  100  grams  of  the  sample  from  the  jar  or  can  into  a 
counterpoised  tin  dish.  Place  the  dish  in  a  drying  oven,  the 
temperature  of  which  is  not  allowed  to  exceed  95°  C.  For 
coal  gas  oxide  it  is  advisable  to  air-dry  the  sample  for  5  to  10 
hours  in  a  warm  place  or  drying  oven  kept  at  55°  C.  Examine 
occasionally  by  removing  from  the  oven  and  allowing  to  cool. 
It  will  be  found  that  some  oxides  containing  much  tarry  matter 
require  several  days  to  dry. 

When  the  oxide  appears  hard  on  cooling,  the  dish  and  con- 


66 

tents  are  weighed  and  a  loss  reported  as  moisture  and  light 
oils. 

The  sample  is  then  ground  in  a  coffee  mill  to  3O-mesh  fine- 
ness, and  quartered  down  until  about  30  grams  are  obtained 
which  are  kept  in  a  well  corked  bottle  for  subsequent  de- 
terminations. 

TOTAL  SULPHUR. 

Laboratory  routine  method,  gravimetric  or  volumetric  as 
desired :  Oxidation  of  Sulphur : — Mix  0.5  gram  of  the  sample 
in  a  100  cubic  centimeter  nickel  crucible  with  5  to  10  grams  of 
sodium  peroxide,  depending  on  the  sulphur  content  of  the 
oxide.  Place  the  crucible  in  a  water  bath  containing  cold 
water,  attach  a  fuse  by  passing  it  through  a  slip  in  the  edge  of 
the  crucible,  put  on  the  cover,  which  must  be  weighted  to  pre- 
vent it  blowing  off,  and  light  the  fuse.  The  fuse  is  prepared 
by  soaking  a  cotton  string  in  a  strong  solution  of  potassium 
nitrate  and  drying.  Transfer  the  fused  mass  to  a  500  cubic 
centimeter  beaker  and  dissolve  it  in  cold  water.  Next,  add 
dilute  HC1  (1:3),  while  stirring,  until  the  iron  precipitate  co- 
agulates in  a  flocculent  form,  but  keep  the  solution  distinctly 
alkaline  to  avoid  the  solution  of  iron  hydroxide.  Heat  to 
boiling,  filter  off  the  precipitate  and  wash  well  with  hot  water. 

Gravimetric  determination  of  sulphur. — Acidify  the  filtrate 
with  dilute  HC1,  heat  to  boiling  and  precipitate  with  barium 
chloride.  Filter,  wash  and  ignite  as  usual  after  two  hours 
standing. 

Volumetric  determination  of  sulphur. — Solutions  required: 
Barium  chromate,  40  grams  dissolved  in  dilute  HC1,  (80  cubic 
centimeters  HC1  specific  gravity  1.2,  920  cubic  centimeters 
H2O,)  approximate  value  of  I  cubic  centimeter  0.04  gram 
BaCrO4.  Sodium  thiosulphate,  N/io,  I  cubic  centimeter 
equals  0.001066  gram  of  sulphur. 

Method. — Catch  the  filtrate  and  washings  in  a  500  cubic 
centimeter  volumetric  flask,  cool,  and  dilute  to  the  mark. 
Transfer  100  cubic  centimeters  of  the  solution  to  a  200.  cubic 
centimeter  volumetric  flask,  add  25  cubic  centimeters  of  barium 


67 

chromate  solution,  shake  for  a  minute  and  then  add  dilute 
ammonia,  a  few  drops  at  a  time,  until  the  color  changes  to  a 
pure  yellow,  indicating  the  complete  precipitation  of  the  ex- 
cess of  BaCrO4.  Dilute  to  i  cubic  centimeter  above  the 
200  cubic  centimeter  mark,  filter  through  a  dry  filter  paper 
into  a  100  cubic  centimeter  flask.  Throw  away  the  first  part 
of  the  filtrate.  Transfer  the  100  cubic  centimeters  of  the 
filtered  solution  to  a  glass  stoppered  bottle,  acidify  with  10 
cubic  centimeters  HC1,  add  I  gram  of  solid  potassium  iodide, 
shake,  and  titrate  the  liberated  iodine  with  N/io  sodium 
thiosulphate. 

Multiply  the  number  of  cubic  centimeters  of  sodium  thio- 
sulphate by  2.132;  this  gives  the  per  cent,  of  sulphur  in  the 
oxide. 

Alternate  method. — Weigh  0.5  gram  of  the  oxide  into  a 
300  cubic  centimeter  Erlenmeyer  flask  and  treat  it  with  30 
cubic  centimeters  of  a  mixture  of  3  parts  HNO3  and  2  parts 
HC1.  Heat  gently  and  when  the  action  ceases  add  a  few  crys- 
tals of  potassium  chlorate,  and  boil.  Add  20  cubic  centimeters 
HC1  and  evaporate  to  dryness  on  a  water  bath.  Heat  in  an 
air  oven  to  110°  C.  for  one  hour  to  dehydrate  silica.  Next, 
cool  the  flask,  moisten  the  mass  with  5  cubic  centimeters  HC1, 
take  up  with  100  cubic  centimeters  of  hot  water,  boil,  filter,  and 
wash  well  with  hot  water.  Dilute  the  solution  to  about  600 
cubic  centimeters  and  precipitate  with  barium  chloride.  Filter 
after  two  hours  standing,  ignite,  and  weigh  the  barium  sul- 
phate in  the  usual  manner. 

SOLUBLE  SULPHUR  AND  TARRY  MATTER. 
EXTRACTION  WITH  CARBON  TETRACHLORIDE. 

Weigh  one  gram  of  the  dried  oxide,  wrap  it  in  a  9  centimeter 
filter  paper.  Place  the  paper  and  contents  in  a  10  cubic  centi- 
meter porcelain  Gooch  crucible,  which  is  equipped  with  an 
aluminum  wire  bail.  Weigh  the  crucible  and  contents  and  sus- 
pend from  the  hook  of  a  Wiley- Soxhlet  extraction  apparatus, 
as  shown  in  Fig.  10.  Fifty  cubic  centimeters  of  carbon  tetra- 
chloride  are  placed  in  the  extraction  flask,  and  the  whole  ap- 


68 


paratus  is  assembled  and  heated  in  a  water  bath.  Boil  the 
water  and  continue  the  extraction  until  the  droppings  from  the 
Gooch  crucible  remain  colorless  for  at  least  a  half-hour.  The 
extraction  will  probably  be  complete  in  three  hours.  Remove 
the  crucible  and  contents  to  a  drying  oven  and  dry  for  one  hour 
or  until  no  odor  of  carbon  tetrachloride  is  apparent.  Weigh 
the  crucible  and  contents.  The  loss  in  weight  will  be  soluble 
sulphur  and  tarry  matter. 


FIG.  10. 

Pour  the  contents  of  the  extraction  flask  into  a  100  cubic 
centimeter  Erlenmeyer  flask,  and  with  a  little  fresh  carbon 
tetrachloride,  wash  out  the  former  flask  into  the  latter.  By 
means  of  a  cork  and  bent  tube,  connect  the  Erlenmeyer  flask 
with  a  Liebig  condenser  and  distil  on  a  water  bath.  When  the 
carbon  tetrachloride  has  been  distilled  off,  add  30  cubic  centi- 
meters concentrated  nitric  acid,  warm  gently  on  a  sand  bath, 
and  add  cautiously,  at  short  intervals,  potassium  chlorate  crys- 


69 


FIG.  lOa. 


tals,  (in  all  about  2  to  3  grams).  Boil  off  the  nitric  acid,  add 
dilute  hydrochloric  acid,  and  precipitate  with  barium  chloride. 
Filter,  dry,  ignite,  and  weigh  the  barium  sulphate.  The  per 
cent,  of  sulphur  found  is  soluble  sulphur,  the  weight  of  which 
deducted  from  the  weight  of  soluble  sulphur  and  tarry  matter 
gives  the  latter. 

Alternate  Method  Using  Carbon  Disulphide. — Proceed  ex- 
actly as  when  using  carbon  tetrachloride  as  described  above, 
taking  care,  however,  to  employ  only  pure,  freshly  distilled 
carbon  disulphide.  When  the  Gooch  crucible  is  removed  from 
the  extractor,  allow  it  to  stand  at  room  temperature  until  all 
odor  of  carbon  disulphide  has  disappeared  before  weighing. 
Caution — Do  not  dry  in  an  oven,  because  of  the  liability  of 
carbon  disulphide  to  spontaneous  combustion.  Empty  and 
wash  the  extraction  flask  into  an  Erlenmeyer  flask,  using  pure, 
freshly-distilled  carbon  disulphide. 

Distil  off  the  carbon  disulphide  and  remove  the  last  traces 
by  means  of  a  current  of  air  applied  to  the  gently  heated  flask. 
Oxidize  the  contents  with  nitric  acid  and  potassium  chlorate 
as  above,  and  precipitate  in  hydrochloric  acid  solution  with 
barium  chloride. 

Note. — Extraction  with  carbon  disulphide  is  liable  to  give 
high  sulphur  results,  due  to  the  decomposition  of  the  solvent 
during  and  subsequent  to  the  extraction.  It  is  therefore  neces- 
sary to  use  only  recently  distilled  carbon  disulphide,  and  when 
the  extraction  is  finished  to  distil  off  and  remove  the  last 
traces  as  rapidly  as  possible.  The  Gooch  crucible  is  used  in- 
stead of  the  usual  extraction  cup  on  account  of  the  convenience 
in  weighing. 


CHAPTER  H. 

GAS  ANALYSIS. 

The  following  determinations  are  covered  in  the  analysis  of 
illuminating  and  furnace  gas  : 
Benzol. 
Illuminants. 
Carbon  Monoxide. 
Hydrogen. 
Methane. 
Ethane. 

Carbon  Dioxide. 
Oxygen. 
Nitrogen. 

Source  of  Method. 

The  method  of  determining  benzol  is  that  due  to  Pfeiffer, 
published  in  Chemiker-Zeitschrift,  1904-28-76. 

The  other  methods  are  those  due  to  the  paper  by  Mr.  E.  H. 
Earnshaw,  published  in  the  JOURNAL,  of  the  Franklin  Institute, 
September,  1898. 

Sampling. 

The  method  of  sampling  depends  upon  whether  it  is  puri- 
fied or  unpurified  under  pressure  or  vacuum.  In  some  in- 
stances, it  is  possible  to  draw  the  samples  directly  into  the 
analyzing  burette,  but  more  often  they  must  be  transferred  to 
the  laboratory  in  containers  specially  provided  for  the  purpose. 
The  figures  show  two  forms  of  gas  sampling  tubes  in  general 
use. 

The  one  shown  in  Fig  n  is  provided  with  cocks,  and  is, 
therefore,  somewhat  more  convenient  than  the  one  shown  in 
the  Fig.  12,  which  must  be  closed  by  sealing  off  the  ends. 
These  tubes  are  very  useful  in  taking  a  sample  sufficient  for  a 
single  analysis,  and  in  the  great  majority  of  cases,  a  tube  of 
this  kind  will  be  all  the  equipment  necessary,  provided  the  gas 
is  under  pressure. 


In  taking  a  sample  with  the  tube  as  shown  in  Fig.  n,  it  is 
first  filled  with  water  and  connected  to  the  gas  supply  by  a 
short  piece  of  hose  which,  together  with  the  connections,  has 
been  thoroughly  purged  of  air  and  dead  gas.  The  water  is 
then  permitted  to  run  out  ahead  of  the  gas,  after  which  the 
outlet  cock  is  closed ;  then  the  inlet,  which  places  the  gas  under 
a  slight  pressure  and  lessens  the  liability  of  air  being  subse- 
quently drawn  in  by  a  leakage  at  the  cock. 


FIG.  11.— Gas  sampling  tube— with  stop  cock 

This  may  be  further  guarded  against  by  dipping  the  ends  of 
the  tubes  in  melted  sealing  wax,  and,  as  an  extra  precaution 
by  placing  sealing  wax  around  the  exposed  portion  of  the 
barrel  of  the  cock.  This  serves  the  double  purpose  of  pre- 
venting the  cock  from  leaking  and  also  from  being  accidentally 
turned. 


FIG.  12. -Gas  sampling  tube  for  sealing. 

In  using  the  tube  described  in  Fig.  12  the  procedure  is  the 
same,  except  that  the  end  is  temporarily  closed  by  means  of  a 
short  piece  of  rubber  tubing  and  a  pinch  cock,  as  shown  in  the 
sketch,  after  the  water  has  run  out.  The  outlet  to  the  tube  is 
then  sealed  off  at  the  construction  by  means  of  a  flame  such 
as  that  furnished  by  a  gasoline  torch  or  a  Bunsen  burner.  A 
candle  flame  may  sometimes  be  used,  but  it  is  rare  that  the 
glass  is  soft  enough  to  make  the  operation  easy.  Having  sealed 
off  the  outlet,  the  inlet  is  closed  in  the  same  way  without  dis- 
connecting from  the  gas  supply. 

When  a  sample  is  to  be  transported  long  distances  or  is  to 


73 


be  preserved  for  any  great  length  of  time  before  analysis,  it  is 
far  better  to  use  sealing  tubes,  as  there  is  no  possibility  of 
leakage  unless  the  end  of  the  tube  is  broken,  and  this  may  be 
largely  guarded  against  by  fusing  the  end  to  a  blunt  point  or 
turning  it  back  upon  itself.  The  tubes  may  be  used  repeatedly 
and  when  the  end  gets  too  short,  a  short  piece  of  glass  tubing 
may  be  sealed  on. 

It  is  sometimes  desirable  to  collect  a  sample  out  of  contact 
with  water.  In  this  event,  if  there  is  an  abundant  supply  of 
gas,  it  should  be  allowed  to  flow  through  the  dry  tube  for  4 
or  5  minutes  in  order  to  displace  the  air,  and  then  sealed  as 
described  above.  When  the  gas  supply  is  small,  mercury 
should  be  used  to  displace  the  air. 


Fig.  13.— Aspirator  for  large  gas  supplies. 

If  a  large  sample  is  required,  the  aspirator  shown  in  Fig. 
13  may  be  employed.  This  consists  of  a  galvanized  iron  cyl- 
inder with  conical  base  and  top  having  a  capacity  of  about 
1/2,  cubic  foot.  The  top  is  provided  with  a  cock  (A)  and  the 
bottom  with  two  cocks  (B)  and  (C)  as  shown.  The  whole 
apparatus  is  mounted  on  a  suitable  tripod  or  stand.  It  is  used 
ordinarily  precisely  as  the  tubes  described  above.  When,  as  is 


74 

sometimes  necessary,  an  average  sample  (of  a  run)  for  a 
definite  period  is  described,  the  cock  B  is  set  so  that  the  water 
will  just  run  out  in  the  stated  time.  The  apparatus  is  then 
filled  with  water  and  the  cock  C  closed.  When  the  apparatus 
is  connected  and  C  is  opened  an  average  sample  of  the  whole 
run  will  be  obtained. 

Aspirating  Tubes. 

In  sampling  gas  from  services  and  moderate  size  mains  and 
connections,  a  fair  average  can  usually  be  obtained  direct 
without  the  use  of  the  aspirating  tube.  If,  however,  the  gas 
chamber  or  passage  is  large,  as  for  example  in  a  generator  or 
large  sized  main,  such  a  tube  must  be  inserted  as  currents  are 
always  set  up,  and  a  sample  taken  simply  through  the  shell 
will  not  give  a  correct  average.  Even  when  a  tube  is  inserted 
to  the  middle  of  the  chamber,  it  is  difficult  to  get  a  true  average 
of  the  gas  passing. 

Glass  aspirating  tubes  should  be  used  when  possible,  as 
they  are  easily  cleaned  and  they  do  not  act  upon,  nor  are  they 
affected  by,  the  gas  passing  through  them.  They  may  be  used 
in  temperatures  up  to  600°  C.  (1,112°  F.).  L,ead  tubes  may 
be  used  up  to  temperatures  of  300°  C.  (527°  F.)  and  are  very 
convenient  as  they  are  easily  handled  and  may  be  bent  into  any 
required  position.  For  temperatures  •  higher  than  600°  C. 
(1,112.°  F.)  porcelain  tubes,  platinum  tubes,  fused  silica  pipes 
may  be  used,  or  water-cooled  iron  tubes.  Fig.  14  shows  a  tube 
which  may  be  made  from  the  ordinary  fittings  procurable 
around  a  gas  works. 

The  tube  shown  in  Fig.  14  is  made  as  follows : 

A  ^4-inch  by  ^-inch  reducing  socket  is  threaded  through 
from  the  inside  to  receive  the  end  of  a  ^-inch  pipe.  Into 
this  socket  is  screwed  a  I Y^ -inch  pipe  threaded  at  both  ends  of 
a  length  depending  upon  the  desired  length  of  the  complete 
apparatus.  On  the  end  of  the  I  %  -inch  tube  is  placed  a  1^2- 
inch  by  i^J-inch  bushing  threaded  from  the  inside  and  through 
which  the  i^-inch  pipe  extends  about  2  inches.  A  I  %  -inch 
cross  is  screwed  on  the  top  of  the  pipe.  One  side  of  the  cross 


75 


contains  a  ij^j-  by  a  ^-inch  bushing  which  carries  a  }/£-inch 
nipple  3  inches  long,  the  other  side  of  the  cross  contains  a 
1 1/2  -inch  by  ^-inch  bushing  which  carries  a  ^-inch  nipple  3 
inches  long,  a  ^-inch  L,  on  the  inside  of  the  cross  and  a  piece 
of  y$ -inch  pipe  of  such  a  length  that  it  extends  to  within  I 
inch  of  the  bottom  of  the  i^-inch  pipe  as  shown  in  sketch. 


Fig.  14.— Water  cooled  sampling  tube. 

The  pipe  B,  which  consists  of  a  piece  of  ^-inch  pipe  threaded 
at  one  end,  is  passed  through  the  top  of  the  T  and  threaded 
through  the  reducing  socket.  The  top  of  the  pipe  is  made 
tight  with  the  top  of  the  cross 'by  means  of  a  lock  nut  or 
stuffing  box.  When  in  use,  the  water  supply  is  connected  to 
pipe  C  and  the  water  overflows  through  the  nipple  B.  The 
complete  apparatus,  when  in  use,  is  held  in  place  by  means  of 


76 


the  bushing  D.    The  sample  of  gas  is  obtained  from  the  outlet 
of  the  pipe  B. 

It  is  of  very  little  use  to  provide  branches  to,  or  a  slit  in, 
the  aspirating  tubes,  as  the  currents  are  of  less  velocity  near 
the  shell  due  to  friction,  and  besides,  with  a  slit  pipe  or  one 
drilled  with  holes,  more  gas  will  be  drawn  in  near  the  sides 
as  the  suction  here  is  strongest.  The  best  method  is  to  set  up 
a  strong  primary  current  and  take  the  sample  from  a  second- 
ary current  at  the  side  of  the  tube  as  shown  in  Fig.  15. 


FIG.  15.— Method  of  supplying  from  large  main. 

Fig.  15  shows  a  glass  tube  inserted  through  a  rubber  stopper 
into  a  i6-inch  condenser  connection.  A  glass  or  metal  T  is 
fastened  close  to  the  end  of  the  tube  by  means  of  heavy  rubber 
hose,  and  the  sample  is  taken  from  the  secondary  current 
flowing  from  A,  the  large  primary  current  all  the  while  flow- 
ing from  B. 

The  foregoing  directions  presuppose  that  the  gas  is  under 
pressure.  If  such  is  not  the  case,  an  aspirating  apparatus 
must  be  employed.  For  small  samples  the  aspirating  bulb 
shown  in  Fig.  16  is  recommended  by  analysts. 


FIG.  16.— Aspirating  bulb. 


77 


This  consists  of  a  small  rubber  bulb  with  valves  working 
opposite  to  each  other,  thus  enabling  it  to  work  as  a  suction, 
and  as  a  pressure  pump.  In  use,  one  end  of  the  empty  gas 
sampling  tube  is  connected  to  the  gas  supply,  and  the  bulb  is 
connected  to  the  other  end,  with  the  valves  in  such  a  position 
that  the  pressure  and  relief  on  the  bulb  will  suck  the  air  out 
and  admit  the  gas.  This  should  be  continued  for  some  time 
to  insure  thorough  displacement  of  the  air.  If  there  is  no 
objection  to  water  coming  into  contact  with  the  gas  or  if  mer- 
cury be  conveniently  used,  a  more  satisfactory  method  is  to 
connect  up  as  shown  in  Fig.  17  in  which  A  is  a  glass  or  metal 


FIG.  17. — Method  of  sampling  from  stack  and  breeching  of  boiler 

aspirating  tube,  B  a  rubber  tube,  C  the  sampling  tube.  The 
whole  apparatus,  including  the  hose  and  tube  A,  is  filled  with 
water  or  mercury,  and  the  tube  introduced  into  the  stack  or 
flue.  Upon  opening  the  cock  on  the  sampling  tube,  the  water 
or  mercury  will  flow  out  and  the  tube  will  materially  increase 
the  pull. 

Where  running  water  is  at  hand,  a  water  suction  pump  may 
be  used  to  advantage.  There  are  many  forms  of  these  pumps 
in  use,  but  for  durability  and  general  adaptability  for  the  pur- 
pose, the  "Chapman"  pump  shown  in  Fig.  18  is  probably  the 
most  satisfactory.  By  its  use  a  strong  primary  sample  may 
be  drawn  off,  and  a  secondary  sample,  taken  from  a  side  con- 
6 


nection  as  previously  explained.  A  steam  jet  aspirator  may 
also  be  employed  in  the  same  way  where  high  pressure  steam 
is  available.  It  is  shown  in  Fig.  19  and  may  be  constructed 
as  follows : 


FIG .  18.—  Chapman  filter  pump . 

The  steam  jet  aspirator  shown  in  Fig.  19  is  made  as  follows : 
Two  24 -inch  nipples  H  and  /  are  threaded  into  a  ^4 -inch  by 
%-inch  reducing  tee  A.  H  is  left  open  for  steam  exhaust, 
while  on  /  is  threaded  a  ^4-inch  union  D,  a  ^-inch  pipe  is  then 
threaded  through  a  ^4 -inch  by  J^-inch  bushing  H,  one  end  of 
which  has  been  hammered  down  to  a  point  leaving  a  i/i6-inch 
opening.  The  ^-inch  bushing  H  is  then  threaded  into  the 
union  B  and  end  of  piece  C  connected  to  steam  supply.  A 
l/4 -inch  nipple  is  then  threaded  into  the  %-inch  connection  on 
tee  A  and  connected  to  place  where  sample  is  to  be  taken  from. 
Where  it  is  necessary  to  take  samples  of  crude  gas,  partic- 
ularly crude  coal  gas  for  the  determination  of  tar,  or  naph- 
thalene, it  is  essential  that  the  temperature  of  the  gas  be  not 
changed  after  the  sample  is  withdrawn  from  the  main.  It  is, 
therefore,  necessary  that  the  sample  tube  be  surrounded  with 
a  water  bath  maintained  at  the  same  temperature  as  the  gas 
in  the  main.  Tubes  similar  to  Fig.  14  should  be  used  for  this 


79 


purpose,  water  at  the  proper  temperature  being  supplied  with 
a  water-jacket. 


FIG.  19.— Steam  or  compressed  air  respirator. 

Where  crude  gas  is  being  sampled  for  its  ammonia  content, 
a  certain  amount  of  ammonia  liquor  exists  as  a  mist  in  the  gas, 
and  at  the  same  time,  the  walls  of  the  main  are  also  coated  with 
ammonia  liquor.  It  is,  therefore,  necessary  to  arrange  the 
inlet  of  the  sampling  tube  so  that  liquor  collected  on  it  from 
the  gas  will  flow  into  the  sample.  This  is  best  secured  by 
placing  an  iron  tube  in  the  main  approximately  83  per  cent,  of 
the  diameter  from  one  side  and  inserting  in  this  a  slightly 
smaller  glass  tube  which  will  be  inclined  to  the  sample  bottle 
so  that  the  ammoniacal  liquor  condensed  in  the  glass  tube  will 
be  collected  in  the  sample. 

Volumetric  Determination  of  Benzols. 
The  determination  depends  on  the  reaction 

N02  4-  3SnCl12  +  6HCI  =  NH2  +  3SnCl4  +  2H2O. 

The  gas  is  treated  in  a  glass  stoppered  separatory  funnel  of 
a  known  content,  the  stopper  and  cork  of  which  have  been 
lubricated  with  a  drop  of  H2SO4,  the  gas  is  allowed  to  blow 


8o 


through  the  apparatus  for  2  minutes,  the  stopper  put  in  place 
and  the  cock  closed.  The  apparatus  is  disconnected  from  the 
source  of  supply  and  the  cock  opened  for  a  moment  to  insure 
atmospheric  pressure,  the  barometer  and  the  thermometer  are 
read.  Two  cubic  centimeters  of  a  mixture  of  equal  parts  of 
concentrated  H2SO4  and  fuming  HNOa  allowed  to  enter  the 
funnel  by  means  of  the  lower  tube,  the  cock  closed,  and  a  half- 
hour  allowed  to  complete  the  absorption  of  the  benzol  vapors. 
Thirty  cubic  centimeters  of  a  concentrated  NaOH  solution  are 
now  added,  and  all  the  vapors  set  free  are  absorbed  by  shak- 
ing. The  solution  is  now  neutralized  with  very  weak  HC1 ; 
no  indicator  is  needed,  as  the  color  of  the  solution  as  it  changes 
from  an  orange  red  of  the  alkaline  state  to  a  wine  yellow  of 
an  acid  state,  is  all  that  is  necessary.  The  solution  is  now  ex- 
tracted twice  with  50  cubic  centimeters  of  ether  shaking  5 
minutes  each  time;  it  is  then  separated  from  the  other  nitro 
products  and  put  into  a  flask  containing  I  gram  of  potash  and 
y2  gram  of  finely  powdered  animal  charcoal,  which  on  shaking 
and  standing,  takes  out  the  strong  yellow  red  coloration. 

The  solution  is  now  filtered  into  a  200  cubic  centimeter 
graduated  flask,  and  washed  with  absolute  ether,  which  is 
evaporated  off  on  a  water  bath.  As  soon  as  this  has  taken 
place,  10  cubic  centimeters  of  absolute  alcohol  and  about  10 
cubic  centimeters  of  a  stannous  chloride  solution  (150  grams 
of  tin  dissolved  in  50  cubic  centimeters  of  HC1  and  made  up 
to  I  liter)  are  added,  and  the  flask  warmed  for  10  minutes  on 
the  water  bath.  The  flask  is  filled  to  the  mark  with  water  and 
20  cubic  centimeters  are  titrated  with  i/io  N.  iodine  solution 
and  starch  paste.  A  blank  is  run  with  10  cubic  centimeters 
of  SnCl2  solution,  10  cubic  centimeters  of  alcohol,  diluted  to 
200  cubic  centimeters  and  20  cubic  centimeters  titrated.  The 
difference  between  the  two  titrations  gives  the  value  of  the 
dinitro  benzol  and  is  calculated  (b  --  a)  10  x  0.0014  gram. 
The  percentage  is  calculated  i  gram  dinitro  benzol  —  0.4643 
gram  C6H6,  I  gram  of  benzol  =  279.2  cubic  centimeters  of 
vapor  of  o°  and  760  millimeters.  The  combined  formulae 
would  appear  as  follows :  J  =  volume  of  gas 


8i 

X 


Vol.    per  cent.  C6H6  =  0.4643  X  279.2 

3690 


x   weight 

of  dinitro  benzol  or  this  can  be  simplified  to  read  where  b  = 
barometer,  t  =  temperature,  g  =  dinitro  benzol  and  /  =  flask 
content. 

Volume  per  cent,  of  benzol  =  (36,090  +  /)  x  g  x  (273  + 
t  +  b). 

It  is  now  generally  admitted  that  the  accuracy  of  a  gas 
analysis  made  by  direct  absorption  in  a  gas  burette  is  not  very 
great,  and  that  the  applicability  of  the  method  is  also  limited 
by  the  fact  that  only  those  absorbents  which  do  not  rapidly 
attack  rubber  can  be  used.  On  the  other  hand  it  is  claimed 
that  the  time  lost  in  connecting  up  absorption  pipettes  and  in 
passing  the  gas  backward  and  forward  is  not  compensated  for 
by  the  increased  accuracy  resulting. 

The  following  apparatus  was  designed  for  the  purpose  of 
meeting  the  above  objection  while  retaining  the  essential  feat- 
ures of  Hempel's  method. 

The  burette  as  seen  in  Figs.  20-21  is  similar  to  that  described 
in  Hempel's  Gas  Analysis  on  page  28,  except  that  a  four-way 
cock  C  replaces  the  three-way  cock  used  by  Hempel  and  the 
burette  is  bulbed,  thereby  shortening  the  same  and  allowing  a 
finer  graduation. 

The  capacity  of  the  burette  is  about  105  cubic  centimeters, 
graduated  in  1/20  cubic  centimeter  from  40  to  102  cubic  centi- 
meters. It  is  connected  through  the  capillary  tube  D  coming 
out  from  the  back  of  the  cock  C  with  manometer  tube  M. 
The  manometer  is  connected  with  the  Petterson  correction 
tube  R.  A  water  jacket  /  surrounds  the  Petterson  tube  and 
burette.  A  potash  absorption  pipette  K  which  rests  on  the 
adjustable  stand  S  is  connected  permanently  with  the  capillary 
tube  B. 

This  modification  of  Hempel's  apparatus  has  the  following 
advantages  : 


82 


i.  It  permits  of  the  potash  absorption  pipette  being  per- 
manently attached  and  so  does  away  with  at  least  five  attach- 
ments and  disengagements  of  a  piece  of  apparatus  disagree- 
able to  handle,  saving  thereby  considerable  time  and  annoy- 
ance ;  for  after  both  the  explosion  and  combustion  the  gas  can 
be  passed  directly  into  the  potash  without  stopping  to  connect 
up  any  other  pipettes.  This  is  also  true  after  the  absorption 
of  illuminants  by  bromine  and  carbonic  oxide  by  cuprous 
chloride  when  it  becomes  necessary  to  remove  the  fumes  of 
bromine  and  hydrochloric  acid. 


FIG.  20. 


2.  With  the  apparatus  constructed  in  the  modified  form  the 
two  limbs  of  the  manometer  tube  and  the  perpendicular  por- 
tion of  the  capillary  tube  coming  out  from  the  back  of  cock 
C  are  in  the  same  plane,  so  that  you  connect  up  the  trouble- 


some  "sagging"  of  the  manometer  tube  common  to  Hempel's 
apparatus  is  overcome. 

3.  The  bulbing  of  the  burette  make  the  apparatus  much  less 
top-heavy  and  cumbersome  and  also  permits  of  a  much  closer 
reading,  as  the  narrowed  portion  may  be  graduated  to  read  to 
1/20  cubic  centimeter  without  trouble. 


FIG.  21. 

Besides  the  above  important  modifications,  several  minor 
changes  have  been  introduced  which  greatly  reduce  the  time 
necessary  for  an  analysis,  while  not  jeopardizing  the  accuracy 
of  the  results. 

The  following  pipettes  and  reagents  are  required  for  the 
analysis : 

A  potash  absorption  pipette  which  is  permanently  attached 
to  the  burette,  as  shown  in  sketch.  (For  reagent  see  page  125.) 

A  pipette  filled  with  strong  bromine  water.     In  order  that 


84 

this  solution  remain  concentrated  an  excess  of  free  bromine 
is  kept  in  the  pipette. 

A  pipette  for  solids  filled  with  stick  phosphorus  covered 
with  water. 

A  double  U.  G.  I.  absorption  pipette.  This  combines  in  one 
piece  of  apparatus  the  two  solutions  of  cuprous  chloride  which 
are  necessary  to  remove  the  carbon  monoxide. 

A  simple  pipette  filled  with  gas-saturated  water  for  storage 
purposes. 

A  mercury  explosion  pipette. 

A  U-shaped  combustion  tube  containing  about  */2  gram 
palladium  black  is  also  required. 

The  following  is  the  method  of  procedure  for  an  analysis  of 
a  gas  containing  CO2,  CMH8M,  O2,  CO,  H2,  CH4,  C,H6>  and  N2. 

Completely  fill  water  jacket  with  distilled  water. 

Turn  cock  C  so  that  the  interior  of  the  burette  Y  communi- 
cates with  A,  open  cock  C,  raise  levelling  bulb  L,  which  has 
been  filled  with  gas-saturated  water,  until  water  flows  out  A. 
Turn  C  so  that  interior  of  burette  communicates  with  K,  and 
draw  over  potash  solution  to  just  above  cock  C. 

Turn  cock  C  so  that  Y  communicates  with  D,  and  by  raising 
and  lowering  L  and  allowing  air  to  escape  through  A,  fill  M 
with  water  to  N.  Open  C  to  A  and  by  lowering  L,  draw  in  air. 
Close  C,  raise  L,  open  C  to  D,  and  admit  air  in  M  to  C,  and 
close  C. 

Disconnect  M  momentarily  at  P  and  reconnect.  The  air  in 
R  is  now  at  atmospheric  pressure. 

Connect  the  tube  containing  gas  sample  with  A,  using  glass 
connector  similar  to  one  used  on  potash  pipette,  being  careful 
to  displace  with  water  all  air  that  may  be  in  connection.  Open 
C  to  A,  lower  L  and  draw  in  100  cubic  centimeters  of  gas. 
Close  C,  raise  L,  open  C  to  D,  and  allow  gas  to  flow  into  M 
until  the  water  level  is  at  O ,  and  close  Z.  Take  the  reading  on 
burette  after  allowing  a  minute  for  water  to  run  down  off 
the  sides  of  the  burette,  add  I  cubic  centimeter  to  observed 
reading  for  the  I  cubic  centimeter  gas  occupying  space  be- 
tween O  and  cock  C.  Disconnect  from  sample  tube  or  gas 


85 

supply  as  the  case  may  be.  Open  C  to  B,  raise  L  and  allow 
gas  to  flow  into  K,  until  the  water  from  burette  reaches  the 
bulbed  portion  of  K,  being  careful  to  draw  the  I  cubic  centi- 
meter from  manometer  and  to  force  that  into  the  potash  like- 
wise. Turn  C  to  D  and  adjust  water-level  at  N  in  M.  Turn 
C  to  B,  lowrer  L,  and  draw  back  gas  until  the  potash  solution 
just  reaches  its  previous  position  above  C  and  close  C.  Raise 
L  and  turn  C  quickly  through  arc  of  180°  so  as  to  allow  no 
gas  to  flow  back  to  B  while  turning  cock  so  that  the  interior 
of  the  burette  communicates  with  manometer  M.  Raise  L 
until  water  in  M  is  level  with  O,  close  Z  and  read  burette, 
adding  i  cubic  centimeter  to  observed  reading  as  before.  The 
difference  between  this  reading  and  the  preceding  gives  direct- 
ly the  percentage  of  CO2  in  the  gas. 

Connect  absorption  pipette  containing  bromine  to  A  resting 
it  on  stand  S,  being  careful  as  before  to  exclude  all  air  from 
connections.  Open  C  to  A,  raise  L,  and  force  gas  from  the 
burette  into  the  pipette  until  water  reaches  the  bulbed  portion 
of  the  pipette,  drawing  the  gas  from  the  manometer  tube  as 
before,  and  close  C.  Shake  the  bromine  pipette  slightly  until 
gas  is  colored  by  bromine  fumes,  open  C ,  lower  L,,  and  draw 
gas  back  into  burette.  Close  C,  raise  L,  C  to  B,  and  force  all 
gas  immediately  into  potash.  Close  C  to  B,  and  open  D,  and 
adjust  water-level.  Open  C  to  B,  lower  L,  and  draw  back  gas 
until  potash  assumes  former  position. 

Close  C,  raise  L,  adjust  water-level  and  read  as  before;  the 
difference  between  this  reading  and  the  preceding  gives  the 
percentage  of  C,,H2,,.  Disconnect  the  bromine  pipette  from 
A  and  connect  the  phosphorus  pipette. 

Force  the  gas  over  the  phosphorus  as  was  done  with  the 
bromine  pipette,  turn  C  to  D,  raise  L  and  adjust  water-level, 
close  C.  If  no  white  fumes  are  given  off  by  the  gas  when 
in  the  pipette  it  is  a  sure  indication  that  all  of  the  CMH2W> 
compounds  in  the  gas  have  not  been  completely  removed.  In 
this  event  it  is  necessary  to  again  pass  the  gas  into  the  bromine 
pipette.  If  fumes  are  given  off,  wait  a  minute  or  two  to  allow 
them  to  partially  condense,  then  open  C  to  A,  lower  L,  and 


86 


draw  gas  back  into  burette.  Close  C,  raise  L,  open  C  to  B,  ad- 
just water-level  at  O,  and  take  reading.  The  difference  between 
this  reading  and  the  preceding  gives  per  cent,  oxygen  present. 
Disconnect  phosphorus  pipette  and  connect  double  absorption 
pipette  containing  cuprous  chloride,  being  careful  to  have  all 
capillaries  filled  with  the  solution.  Open  C  to  A,  raise  L,  and 
force  all  gas  over  one  solution  of  cuprous  chloride.  Shake  for 
two  or  three  minutes  and  then  draw  gas  back  into  burette  until 
solution  just  passes  cock  on  cuprous  chloride,  pipette,  turn  this 
cock  so  as  to  connect  with  other  solution  of  cuprous  chloride, 
raise  L,  and  force  gas  over  second  solution  to  remove  last  of 
carbon  monoxide,  and  close  C.  Shake  for  a  few  minutes, 
draw  gas  back  into  burette,  and  then  immediately  force  it  into 
the  potash  pipette.  Adjust  water-level,  draw  gas  back  from 
potash  pipette  and  take  reading. 

The  difference  between  this  reading  and  the  preceding  gives 
percentage  of  carbon  monoxide. 

It  is  important  to  notice  that  even  with  the  precaution  of 
using  two  pipettes  with  freshly  prepared  cuprous  chloride  the 
absorption  of  the  carbonic  oxide  is  seldom  complete,  usually 
a  trace  remaining  unabsorbed.  However,  this  fact  introduces 
no  error  in  the  analysis,  as  this  residue  of  carbonic  oxide  can 
be  determined  by  the  combustion  made  to  determine  hydrogen. 

The  residue  of  the  gas  mixture  remaining  after  the  absorp- 
tions may  consist  of  the  following : 

H2  +  CO  +  N2  +  CH4  +  C2H6,  C3H8,  etc. 

For  all  ordinary  purposes  it  is  sufficient  to  assume  that  the 
highest  paraffine  present  is  C2H6,  as  all  others  higher  than  this 
exist  only  in  traces. 

There  being  no  satisfactory  known  absorbent  for  any  of 
these  gases,  recourse  is  had  to  the  method  of  combustion. 

The  analysis  is  accordingly  continued  as  follows : 

The  double  absorption  pipette  is  replaced  by  the  storage 
pipette  containing  gas-saturated  water.  Pass  approximately 
15  cubic  centimeters  of  the  residue  back  into  the  potash  by 
opening  Z,  raising  L  and  opening  C  to  B.  Turn  C  to  A,  and 


87 

pass  remainder  of  residue  into  storage  pipette.  Close  pipette 
with  a  pinch-cock  and  disconnect.  Adjust  water-level  in  M 
at  N.  Turn  C  to  A  and  by  lowering  L,  draw  into  the  burette 
about  85  cubic  centimeters  of  air.  Close  C  raise  L  and  open 
C  to  D  draw  the  gas  stored  over  the  potash  into  the  burette, 
close  C  raise  L,  turn  C  quickly  through  arc  of  180°  to  connect 
with  D  adjust  water-level  at  0,  close  Z  and  take  reading.  The 
increase  over  the  previous  reading  is  the  amount  of  gas  taken 
for  the  explosion. 

Connect  mercury  explosion  pipette  at  A  and  pass  mixture 
of  gas  and  air  into  pipette  and  explode,  first  partly  withdraw- 
ing glass  connecting  tube  from  rubber  connection  and  placing 
clip  on  same. 

Adjust  water-level  in  M  at  N,  draw  back  gas  from  explosive, 
pipette  and  measure  contraction  resulting  from  the  explosion. 
Pass  the  gas  into  potash,  and  the  resulting  contraction  gives  the 
amount  of  carbonic  acid  formed  during  the  explosion.  Dis- 
connect explosion  pipette  and  connect  phosphorus  pipette. 
Pass  gas  residue  over  phosphorus  to  remove  all  oxygen  in  ex- 
cess of  that  which  was  required  for  explosion  and  measure  the 
amount  of  nitrogen  left.  This  gives  nitrogen  introduced  with 
gas.  By  subtracting  amount  of  air  used  for  explosion  X  79.2 
from  this  reading,  one  obtains  nitrogen  introduced  with  gas 
for  explosion.  This  multiplied  by  factor  obtained  by  dividing 
the  amount  of  gas  residue  taken  for  the  explosion  into  the 
whole  amount  of  gas  left  after  absorbing  carbon  monoxide, 
gives  the  total  nitrogen  in  the  original  sample  of  gas  taken  for 
analysis.  The  percentage  of  nitrogen  thus  obtained  should 
check  that  obtained  by  subtracting  the  sum  of  the  other  con- 
stituents in  the  gas  from  100. 

The  equations  obtained  from  the  explosion  are  as  follows : 

(1)  Contraction  in  volume  =  3/2H2  +  ^CO  +  2CH4  -f- 
2/2C2H, 

(2)  CO2  formed  =  CO  +  CH4  +  2C2H6. 

(3)  Residual  nitrogen  =  N2  -(-  N\. 

Where  N±  is  the  nitrogen  introduced  with  the  air. 


88 


An  examination  shows  that  the  equations  I  and  2  contain  4 
unknown  quantities  and  therefore  two  more  equations  are 
needed  for  the  solution.  Fortunately,  the  method  of  frac- 
tional combustion  over  palladium  affords  the  needed  informa- 
tion. As  is  well  known,  when  a  mixture  of  hydrogen  and  CH4 
with  oxygen  or  air  is  passed  over  heated  palladium  black,  the 
hydrogen  burns  to  H2O,  but  the  CH4  remains  unaltered.  If 
CO  and  any  of  the  higher  paraffines  are  also  present,  the  CO 
burns,  but  the  paraffines  do  not. 

Returning  to  the  analysis,  proceed  as  follows :  Fill  burette 
to  A  by  raising  L,  adjust  water-level  at  N  in  M.  Draw  in 
about  70  cubic  centimeters  air  and  measure  it. 

Connect  storage  pipette  and  draw  in  about  30  cubic  centi- 
meters gas  residue,  and  measure,  the  increase  in  volume  giving 
the  amount  of  gas  taken  for  combustion. 

Place  explosion  pipette  with  mercury  level  about  one-half 
up  to  capillary,  on  stand  S,  connect  combustion  tube  to  A  and 
explosion  pipette,  equalize  pressure  in  combustion  tube  and 
gas  burette  and  re-measure  gas  in  burette.  Place  combustion 
tube  in  hot  water  by  resting  beaker  containing  water  on  T 
and  pass  gas  mixture  backward  and  forward  over  palladium 
until  there  is  no, further  contraction,  measure  gas  and  decrease 
in  volume  gives  contraction  due  to  combustion  of  hydrogen 
and  carbon  monoxide.  The  equations  are : 

(4)  Contraction  in  volume  =  3/2H2  -|-  ^CO. 

(5)  CO2  formed  =  CO. 

From  these  two  equations,  the  value  of  hydrogen  and  CO 
may  be  readily  determined. 

For  the  sake  of  simplicity,  let  us  now  assume  that  the  same 
quantity  of  gas  residue  was  used  in  both  the  explosion  and 
the  combustion. 

We  may  then' subtract  equation  (4)  from  (i)  and  (5)  from 
(2),  whence,  designation  the  difference  between  the  contrac- 
tion due  to  combustion  by  the  letter  (a)  and  the  difference  in 
the  CO2  formed  by  the  letter  (b)  we  find 

(6)     2  CH4  +  2-y2  CXT  =  *• 


89 

(7)     CH4+  2C,H~ 
whence  (8)     C2H7=  ^  ~  2 

o 

and  (9)     CH4  -        ~ 


o 

A  very  useful  check  on  the  accuracy  of  this  determination  is 
obtained  from  the  following  : 

Volume  of  gas  taken  for  explosion  =  H2  +  N2  +  CO  + 
CH4  +  C2H7     H2  +  CO  are  found  by  (4)  and  (5),  and  AT  is 
given  by  (3). 
Therefore,  we  have 

(10)  Volume  taken  =  (H2  +  N2  +  CO)  =  CH4  +  C2H6 
and  this  value  should  be  the  same  as  the  algebraic  sum  of  (8) 
and  (9)  or 

(n)  Volume  taken  +  (H2  +  N2  +  CO)  =  2a  ~  b  . 

\} 

This  method  if  carefully  pursued  will  give  results  that  are 
extremely  accurate,  and  what  is  much  to  be  desired,  the  method 
is  very  rapid.  Analyses  have  repeatedly  been  made  in  from 
30  to  35  minutes. 

The  Modified  Elliott  Gas  Analysis  Apparatus. 

This  apparatus  is  shown  in  Fig.  22.  It  consists  of  three 
glass  tubes  marked  A,  B,  and  C,  mounted  on  an  iron  stand. 

Tube  A,  called  the  absorption  or  laboratory  tube,  has  a  one- 
way stop-cock,  i,  at  the  top,  and  three-way  stop-cock  at  the 
bottom,  2.  The  funnel,  3,  is  ground  to  fit  the  top  of  A,  and 
has  two  marks  10  cubic  centimeters  and  20  cubic  centimeters 
etched  on  the  glass.  The  lower  outlet  of  cock  2,  drains  to  the 
sink  through  a  piece  of  rubber  tubing.  The  side  outlet  is 
connected  with  level  bottle,  4,  by  another  piece  of  rubber  tubing 
which  is  long  enough  to  allow  bottle  4  to  be  placed  on  the 
shelf  above  the  apparatus.  There  is  a  100  cubic  centimeter 
mark  near  the  lower  end  of  A. 


FIG.  22. 


Tube,  B,  is  called  the  explosion  tube.  It  is  graduated  to 
100  cubic  centimeters  in  i/io  of  a  cubic  centimeter.  It  has  a 
three-way  stop-cock,  5,  the  arms  of  which  are  connected  to 
tubes  A  and  C  by  means  of  short  pieces,  of  rubber  tubing,  the 
connections  being  made  by  bringing  the  glass  side  pieces  close 
together  and  fastening  the  rubber  with  fine  wire.  The  level 
bottle,  6,  is  connected  with  the  lower  end  of  B  by  a  rubber  tube 
long  enough  to  allow  the  bottle  to  be  placed  on  the  shelf  above. 
The  upper  end  of  B  has  two  platinum  wires  fused  into  the 
glass.  The  electrodes  are  attached  to  these  wires  when  the  gas 
is  to  be  exploded.  B  is  enclosed  in  a  water-jacket  which  ex- 
tends from  the  platinum  wires  to  below  the  100  cubic  centi- 
meter mark. 

Tube  C,  called  the  residual  tube,  is  a  plain  glass  tube  having 
a  one-way  stop-cock,  7,  and  a  level  bottle  8.  Connection  is 
made  with  B  as  described  above. 

REAGENTS. 

Sodium  hydroxide  10  per  cent,  solution. 

Pyrogallic  acid  10  per  cent,  solution,  used  by  mixing  in  the 
funnel  with  equal  volume  of  10  per  cent,  sodium  hydroxide. 

Acid  cuprous  chloride,  made  as  follows : 

Four  hundred  grams  chloride  dissolved  in  1,800  cubic  centi- 
meters hydrochloric  acid,  (specific  gravity  1.2)  to  this  solution 
add  400  cubic  centimeters  water.  This  solution  is  to  be  kept 
in  a  bottle  containing  pieces  of  copper  wire. 

Fill  bottles  4,  6,  and  8  with  water  and  place  them  on  the 
shelf  above  the  apparatus.  Open  stop-cock  i,  turn  5  so  that  C 
is  connected  with  A.  Then  open  7,  allowing  water  from  bottle 
8  to  fill  tube  C  and  pass  into  A.  Close  7  and  turn  5  so  that  B 
is  connected  with  A,  allowing  water  from  6  to  fill  B  and  pass 
into  A,  then  shut  off  5.  Turn  2  so  that  water  from  4  fills  A 
and  flows  out  at  i,  then  close  i.  The  apparatus  is  now  filled 
with  water  and  the  next  step  is  to  transfer  the  gas  into  it  from 
the  collection  tube.  Before  doing  this,  examine  the  apparatus 
to  see  if  there  are  any  air  bubbles  imprisoned  in  it,  paying 
particular  attention  to  the  capillary  tubes  in  the  upper  part.  If 


92 

any  bubbles  are  seen,  drive  them  out  with  water  from  the  level 
bottles. 

The  sample  of  gas  is  transferred  to  the  apparatus  by  remov- 
ing funnel  3,  replacing  it  with  a  piece  of  soft  rubber  tubing 
which  is  filled  with  water,  and  attaching  the  collection  tube  and 
passing  the  gas  into  A  in  the  usual  manner.  When  the  gas  fills 
A  to  below  the  100  cubic  centimeter  mark,  cock  i  is  closed  and 
the  collection  tube  detached. 

METHOD  OF  ANALYSIS. 

Place  the  funnel  3  on  the  tube  A.  Set  bottle  4  on  the  shelf 
and  bottle  6  on  the  table.  Turn  cock  5  to  connect  B  with  A 
and  turn  cock  2  so  that  the  gas  in  A  passes  slowly  into  B. 
While  the  gas  is  passing  into  B,  raise  bottle  6  and  hold  it  so 
that  its  water-level  coincides  with  the  100  cubic  centimeter 
mark  on  B,  and  at  the  same  time  regulate  the  speed  of  the 
gas  by  manipulating  cock  2.  When  the  meniscus  in  B  reaches 
the  100  cubic  centimeter  mark,  close  cock  2,  and  without  chang- 
ing the  position  of  bottle  6,  reach  up  and  close  cock  5.  Place 
bottle  6  on  the  table  and  wait  one  minute  to  allow  the  water 
adhering  to  the  inside  of  B  to  run  down,  then  raise  bottle  6 
bringing  its  water-level  to  that  in  B  and  verify  the  volume 
in  B. 

Note. — If  the  transfer  of  gas  from  A  to  B  is  done  very 
slowly,  it  will  be  found  that  the  water  adhering  to  the  inside  of 
B  will  all  have  run  down  at  the  same  time  that  the  meniscus 
in  B  reaches  the  100  cubic  centimeter  mark. 

After  making  sure  that  there  is  a  volume  of  100  cubic  centi- 
meters of  gas  in  B,  place  bottle  4  on  the  shelf,  open  cock  i  and 
turn  cock  2  so  that  the  water  in  4  will  drive  out  the  gas  left  in 
A.  Open  cock  7  and  allow  the  water  from  C  to  pass  into  A 
driving  out  the  gas  left  in  the  capillary  tubes  between  B  and  A. 
Close  cocks  7  and  i. 

It  will  be  noticed  that  there  is  a  little  gas  above  the  zero 
mark  in  tube  B.  This  is  less  than  i/ioth  of  a  cubic  centimeter 
and  may  be  ignored,  or  it  may  be  compensated  for  during  the 


93 

analysis  by  allowing  the  water  from  A  to  come  only  to  the 
cock  5  when  gas  is  being  transferred  from  A  to  B. 

Place  bottle  4  on  the  table  and  bottle  6  on  the  shelf,  turn 
cock  5  to  allow  the  gas  in  B  to  pass  into  A.  When  the  water 
from  B  has  reached  the  capillary  above  the  bulb  of  A,  close  5. 
Do  not  allow  any  unnecessary  water  to  flow  from  B  into  A. 
Now  pour  10  cubic  centimeters  of  the  sodium  hydroxide  re- 
agent into  the  funnel  3,  and  slightly  open  i,  allowing  the  re- 
agent to  pass  into  A.  At  the  same  time,  manipulate  I,  and 
give  the  whole  apparatus  a  rotary  motion  on  its  base  to  spread 
the  reagent  over  the  inner  surface  of  A.  Let  the  reagent  enter 
slowly  and  spread  evenly.  Use  only  10  cubic  centimeters  of 
this  reagent;  it  is  unnecessary  and  dangerous  to  use  more,  be- 
cause 10  cubic  centimeters  will  absorb  about  50  cubic  centi- 
meters of  CO2  and  any  excess  is  liable  to  absorb  a  few  tenths 
of  a  cubic  centimeter  of  illuminants  for  every  10  cubic  centi- 
meters of  the  reagent.  Close  cock  I  when  the  reagent  is  near 
the  bottom  of  the  funnel,  and  be  careful  not  to  allow  any  air 
to  enter  tube  A. 

Open  cock  5  slightly,  allowing  water  from  B  to  wash  out 
any  reagent  that  may  have  crept  into  the  capillary  tubes  be- 
tween A  and  B.  Place  bottle  4  on  the  shelf  and  bottle  6  on 
the  table  and  drive  the  gas  from  A  into  B,  shutting  cock  5  when 
the  water  from  A  reaches  it.  When  the  gas  is  back  in  B  and 
cock  5  closed,  open  cock  i  and  turn  cock  2  so  that  the  water 
in  A  will  pass  through  its  lower  outlet  into  the  sink. 

When  A  is  empty,  fill  funnel  3  with  water  and  allow  this 
water  to  flow  down  and  spread  on  the  inside  of  A  in  the  same 
manner  that  the  reagent  was  applied.  This  washes  tube  A  clean. 
While  doing  this,  open  cock  7  to  allow  water  from  C  to  wash 
out  the  capillary  tubes.  Close  cock  7,  When  A  is  thoroughly 
washed,  turn  cock  2  to  connect  its  lower  outlet  with  bottle  4 
thus  washing  out  the  rubber  tube  connecting  A  and  4.  Turn 
cock  2  so  that  its  lower  outlet  connects  with  A,  fill  the  funnel 
with  water  and  again  wash  out  A.  Turn  cock  2  so  that  water 
from  4  may  enter  A  and  when  the  water  reaches  the  10  cubic 
centimeter  mark  on  the  funnel,  close  cock  i. 
7 


94 

Now  take  bottle  6  from  the  shelf  and  bring  its  water-level 
to  the  meniscus  in  B,  and  carefully  note  the  graduation  on  B 
where  the  two  levels  coincide.  Note  the  reading.  This  read- 
ing subtracted  from  100  will  be  the  percentage  of  carbon  di- 
oxide, CO2  in  the  gas. 

The  above  method  of  applying  reagents,  manipulating  the 
apparatus,  excluding  air  and  washing  out  and  preparing  for  the 
next  absorption  refers  to  all  subsequent  operations  except  the 
following : 

Illuminants  are  absorbed  by  adding  3  drops  of  bromine  to 
the  water  in  the  funnel  and  causing  the  bromine  to  enter  A 
very  slowly  and  spread  evenly,  sodium  hydroxide  is  then  used 
to  absorb  the  bromine  vapors. 

Caution. — The  bottle  from  which  the  bromine  is  taken 
should  never  be  lifted  to  the  funnel  3,  as  serious  accidents  may 
occur.  This  bottle  should  be  on  the  table  and  the  small  quan- 
tity needed  removed  by  a  pipette  dropper  to  the  funnel. 

Oxygen  is  absorbed  by  a  mixture  of  5  cubic  centimeters 
each  of  the  pyrogallic  acid  and  sodium  hydroxide  solutions. 
These  are  poured  into  the  funnel  from  their  respective  bottles, 
and  well  mixed. 

Carbon  monoxide  is  absorbed  by  20  cubic  centimeters  of  acid 
cuprous  chloride  solution.  This  reagent  must  be  added  a  little 
at  a  time,  waiting  half  a  minute  between  each  addition  as  its 
action  is  slow.  After  absorption  of  CO  place  about  10  cubic 
centimeters  of  water  in  the  funnel  and  allow  it  to  enter  A, 
spreading  evenly  and  washing  down  the  white  salt.  The  ob- 
ject of  adding  water  is  to  absorb  the  acid  vapors. 

The  residual  gas  consisting  of  hydrogen,  methane  and  nitro- 
gen is  passed  into  tube  C  retaining  12  cubic  centimeters  in  tube 
B.  Tube  A  is  filled  with  air  to  the  100  cubic  centimeter  mark 
and  air  is  passed  from  A  into  B  mixing  with  the  12  cubic  centi- 
meters of  gas  until  the  volume  in  B  is  about  72  cubic  centi- 
meters. This  proportion  is  not  absolute  and  must  be  found  by 
experiment  as  it  varies  for  different  gases.  The  above  volume 
is  usually  correct  for  carbureted  water-gas.  The  excess  air 
in  A  is  expelled,  and  the  contents  of  B  passed  to  and  fro  be- 


95 

tween  B  and  A  to  thoroughly  mix.  When  finally  mixed  the 
volume  in  B  is  read,  bottle  6  is  placed  on  the  floor  and  the  gas 
exploded  by  an  electric  spark.  After  waiting  three  minutes 
the  volume  in  B  is  read.  The  CO2  formed  by  the  explosion 
is  absorbed  by  the  sodium  hydroxide,  the  gas  is  then  passed 
back  to  B  and  the  volume  again  read.  The  oxygen  remaining 
in  the  gas  is  then  absorbed  by  alkaline  pyrogallol  and  the  final 
volume  read. 

The  hydrogen,  methane  and  nitrogen  are  calculated  as  fol- 
lows :  Let  R  be  the  residual  gas,  T  the  gas  taken  for  explosion 
(12  cubic  centimeters),  C  the  contraction  after  explosion.  D 
the  CO2  absorbed.  Then, 

Hydrogen  in  T  =  2C~4D  (H  T) ;  Hydrogen  in  R  =-H 


Methane  is  T  .=  D;  Methane  in  R  = 


T 
D  X  R 


The  sum  of  all  the  constituents  subtracted  from  100  will  give 
the  nitrogen.  There  are  two  methods  of  varifying  the  above 
results : 

1.  Subtract  the  sum  of  the  hydrogen  and  methane  in  T  from 
T,  multiply  this  result  by  R  and  divide  by  T.     This  gives  the 
per  cent,  of  nitrogen  which  should  come  within  i/io  of  one 
per  cent,  of  the  nitrogen  found  by  difference.     Expressed  in 
formulas  this  would  be, 

NT  V  R 
T  —  (HT  -f  D)  =  Nitrogen  in  T.     ^^~-     ^Nitrogen  in  gas. 

2.  Multiply  the  air  added  by  0.791 ;  this  gives  the  nitrogen 
in  this  air  volume.     Subtract  this  from  the  final  reading;  this 
gives  the  nitrogen  in  T,  (NT).     Multiply  this  result  by  R  and 
divide  by  T.     This  gives  the  nitrogen  in  the  gas.     Expressed 
in  formulas  this  would  be: 

Volume  i  — T  =  air  taken  for  explosion,  (A) 

A  X  0.791  =  nitrogen  in  A,  (NA) 

Final  reading — NA  =  nitrogen  in  T,   (NT) 

NT  X  R 

— = —      =  nitrogen  in  gas. 


96 

This  result  should  agree  within  one  per  cent,  of  the  nitrogen 
found  by  difference.  If  all  the  calculations  have  been  found 
correct  and  a  difference  exists  then  this  is  due  to  the  presence 
of  ethane.  In  this  case  the  per  cent,  of  nitrogen  found  by 
method  2  is  added  to  the  sum  of  all  the  other  constituents, 
except  methane,  and  the  difference  between  this  sum  and  100 
considered  as  methane. 

The  Morehead  Apparatus. 

This  type  of  apparatus  has  been  used  for  the  past  fifteen 
years  in  the  laboratories  of  The  Peoples  Gas  Light  and  Coke 
Company  of  Chicago,  and  by  other  large  companies. 

The  gas  analyzing  apparatus  as  shown  in  Fig.  23  consists 
of  a  graduated  burette  (4)  fitted  with  platinum  electrodes  (13) 
and  a  storage  bulb  (6).  The  three  aspirator  bottles  (7,  8  and 
9)  with  rubber  tubing  (14,  15,  16  and  17),  and  an  electric 
sparking  outfit  are  also  required.  Both  glass  pieces  are  fitted 
with  three-way  cocks  (i,  2  and  3).  The  measuring,  explosion, 
washing,  and  the  entire  analysis  is  made  in  the  graduated, 
burette;  the  bulb  (6)  is  used  only  for  storage  of  the  reserve 
supply  of  gas  after  the  CO  absorption  in  case  the  explosion  is 
unsatisfactory.  The  burette  (4)  is  usually  provided  with  a 
water-jacket  (n)  consisting  of  a  large  glass  tube  confining 
by  large  rubber  stoppers  at  the  ends  clear  distilled  water.  A 
bottle  or  beaker  (10)  is  placed  under  cock  (2)  to  form  a  seal 
and  catch  waste  reagents  and  wash  water.  A  removable  fun- 
nel or  cup  (5)  is  attached  to  burette  capillary  tube  at  the  top 
by  a  ground  joint.  A  secondary  funnel  (12)  beneath  (5) 
serves  to  drain  away  excess  reagent  or  wash  water  by  means 
of  drain  tube  (18). 

In  preparing  the  apparatus  for  an  analysis,  first  fill  the  as- 
pirator and  seal  bottles  (8,  9  and  10)  and  the  levelling  bottle 
(7)  with  distilled  water  previously  saturated  at  the  tempera- 
ture of  the  water- jacketed  buretted  with  the  gas  to  be  analyzed, 
and  place  aspirator  bottles  (7,  8  and  9)  on  shelf  (21).  By 
manipulating  cock  (3)  displace  all  air  from  rubber  tubing 
(15,  1 6  and  17)  until  water  entirely  free  of  bubbles  flows  up- 


97 


ward  through  ground  joint  into  cup  (5).    Then  open  cock  (2) 
to  seal  bottle  (10)  and  purge  all  air  out  of  tube  (14)  through 


FIG.  23. 


cock  (2)  into  seal  bottle  (10).  Similarly  open  cock  (2)  to 
burette  (4)  and  fill  same  with  water  up  to  funnel.  When  the 
apparatus  is  quite  full  of  water,  as  described,  remove  cup  (5) 


98 

open  cock  on  sampling  can  or  pipe  from  which  the  sample  is 
to  be  taken,  allow  gas  to  blow  through  the  hose  for  a  few 
seconds  to  insure  the  explosion  of  all  air,  and  then  attach 
hose  to  the  ground  joint  end  of  the  capillary  tube  at  the  top  of 
the  burette.  Turn  cock  (2)  so  that  the  water  in  burette  (4) 
communicates  with  the  levelling  bottle  (7),  held  level  with  fun- 
nel (5).  Now  open  cock  (i)  so  that  the  gas  sample  enters 
burette  only,  and  as  the  surface  of  water  in  the  burette  (4) 
is  depressed,  slowly  lower  the  levelling  bottle  (7),  keeping  the 
surface  of  water  in  same  slightly  above  that  in  the  burette  in 
order  to  insure  no  inward  leaks  of  air  through  loosely  attached 
tubing,  etc.  When  the  gas  has  displaced  nearly  all  water  to 
about  a  point  (19)  in  the  burette,  close  cock  (i),  remove 
rubber  tubing  at  top  of  burette  and  replace  cup  (5).  Open 
cock  (3)  for  a  few  seconds  and  expel  gas  from  capillary  tubes 
until  water  flows  into  cup  (5)  and  fills  it  about  one-quarter 
full.  If  the  sample  is  taken  from  the  house  piping,  or  where 
there  is  an  abundant  sample,  it  is  well  to  allow  the  gas  to  flow 
entirely  through  the  burette  and  out  at  the  lower  stop-cock  for 
a  few  seconds,  care,  of  course,  being  taken  to  purge  out  excess 
gas  from  stem  of  cock  (2)  into  bottle  (10)  before  securing  the 
100  cubic  centimeter  sample  for  analysis. 

If  the  gas  sample  be  at  a  different  temperature  than  the 
burette,  allow  it  to  remain  in  the  burette  for  a  few  minutes 
before  proceeding  to  secure  the  desired  100  cubic  centimeters. 
When  the  gas  has  assumed  the  temperature  of  the  burette,  raise 
levelling  bottle  (7)  so  that  the  water-level  is  sufficiently  above 
the  100  cubic  centimeter  graduation  of  the  burette  to  force 
small  bubbles  of  the  confined  sample  through  the  water  into 
cup  (5),  when  the  cock  (i)  is  slightly  opened.  Bubble  excess 
gas  sample  slowly  outward  in  this  manner  until  closing  cock 
(i)  and  lowering  bottle  (7),  its  water-level  and  that  in  the 
burette  are  at  the  100  cubic  centimeter  mark.  If  the  zero 
mark  of  the  burette  be  at  the  cock  (i),  then  the  100  cubic 
centimeter  mark  is  taken  for  a  levelling  point  as  just  described, 
but  if  the  zero  graduation  be  at  the  point  of  capillary  retention, 
where  the  capillary  tube  immediately  below  cock  (i)  widens 


99 

into  the  burette  proper,  then  excess  gas  is  bubbled  outward, 
until  the  water-levels  in  the  bottle  (7)  and  burette  (4)  are  at  a 
mark  equal  to  100  cubic  centimeters,  minus  the  previously  de- 
termined volume  (usually  0.3  or  0.4  cubic  centimeter)  of  the 
capillary  tube  between  cock  ( I )  and  the  zero  graduation  at  the 
point  capillary  retention.  In  the  latter  case,  after  adjusting 
the  burette  water-level  a  99.7  or  99.6,  as  the  case  may  be, 
bottle  (7)  is  placed  on  a  level  with  (10)  and  the  cock  (i)  is 
slightly  opened  until  the  water  in  cup  (5)  slowly  enters  the 
burette  capillary  tube  at  the  top  to  the  point  of  capillary  re- 
tention, when  it  will  be  found  upon  raising  bottle  (7)  that  the 
water-level  corresponds  with  the  one  in  the  burette,  which  will 
be  at  the  100  cubic  centimeter  graduation. 

When  there  is  just  100  cubic  centimeters  in  the  burette  the 
analysis  may  be  started. 

Turn  the  cock  (2)  so  as  to  connect  the  burette  with  the 
bottle  (10)  raise  the  funnel  (5)  until  it  is  just  off  its  ground 
joint  and  drain,  leaving  about  Y^  inch  of  water  in  the  bottom. 
L/ower  the  funnel  onto  its  seat  and  put  into  it  about  20  cubic 
centimeters  of  potassium  hydrate  solution.  Be  sure  that  cock 
(2)  is  set  so  that  the  burette  is  connected  with  (10).  Now 
open  cock  (i)  and  let  the  potassium  hydrate  solution  drain 
very  slowly  into  the  burette.  When  it  has  nearly  all  gone  into 
the  burette  close  cock  (i)  and  open  cock  (3)  and  let  water 
from  bottle  (8)  or  (9)  through  into  the  funnel  (5)  for  about 
ten  seconds.  Rinse  the  funnel  and  fill  it  with  about  50  cubic 
centimeters  of  distilled  water  previously  saturated  with  the  gas 
being  analyzed.  Pass  this  wash  water  slowly  through  the 
burette.  Then  turn  cock  (2)  so  that  burette  is  connected  with 
bottle  (7),  and  read  the  contraction  of  the  gas,  at  the  same 
time  holding  the  bottle  (7)  with  the  surface  of  the  water  in 
the  bottle,  level  with  the  surface  of  the  water  to  the  burette; 
also  note  the  reading  on  the  burette  graduations  coinciding 
with  the  bottom  of  the  meniscus  of  the  water-level  in  the 
burette.  The  amount  absorbed  as  indicated  by  the  contraction 
in  cubic  centimeters,  or  difference  in  cubic  centimeters,  be- 


IOO 


tween  the  100  and  the  burette  reading,  equals  the  per  cent,  of 
carbon  dioxide. 

Turn  cock  (2)  to  connect  the  burette  with  the  bottle  (10), 
and  with  a  I  cubic  centimeter  pipette  put  about  two  drops  of 
bromine  into  the  funnel  (5)  which  should  contain  about  20 
cubic  centimeters  of  distilled  water.  Drain  this  slowly  into 
the  burette,  as  in  the  previous  operation,  until  the  entire  gas 
space  in  the  burette  is  filled  with  reddish  brown  bromine 
fumes,  then  admit  the  rest  of  the  bromine  and  most  of  the 
water  in  the  funnel.  Next  pour  into  the  funnel  about  30  cubic 
centimeters  of  potassium  hydrate  solution  and  drain  part  of 
this  solution  in  slowly  until  the  water  ceases  to  rise  and  the 
burette  and  the  surface  of  the  water  are  quite  free  from 
bromine  fumes.  Wash  with  about  75  cubic  centimeters  of 
aerated  distilled  water.  Wait  two  minutes  and  measure  as 
explained  above.  The  amount  absorbed  in  cubic  centimeters 
equals  the  per  cent,  of  illuminants. 

Now  place  in  cup  (5)  about  20  cubic  centimeters  of  pyro- 
gallic  acid  solution,  and  add  20  cubic  centimeters  of  KOH 
solution  and  allow  mixing  to  take  place  naturally  for  about 
ten  seconds,  then  drain  this  through,  wash  out  the  burette  with 
about  75  cubic  centimeters  of  distilled  water  and  measure  in 
the  way  previously  explained,  after  waiting  at  least  two 
minutes  for  gas  to  resume  temperature  of  burette  jacket.  The 
resulting  contraction  in  cubic  centimeters  equals  the  per  cent, 
of  oxygen. 

Next  place  about  40  cc.  of  copper  monochloride  solution  in 
the  funnel  and  drain  through  very  slowly  until  no  further 
contraction  is  observed.  Then  if  no  reagent  remains  in  cup 
(5)  add  10  cubic  centimeters  of  same  reagent  and  pass  it 
through  the  burette.  Pass  in  about  50  cubic  centimeters  of 
distilled  water  and  after  this  10  cubic  centimeters  KOH  solu- 
tion, drain  through  and  wash  out  with  about  100  cubic  centi- 
meters of  distilled  water.  The  amount  absorbed  in  cubic  centi- 
meters equals  the  per  cent,  of  carbon  monoxide.  This  re- 
agent should  be  added  rather  slowly  and  several  minutes  al- 
lowed for  its  action  on  the  CO. 


IOI 

The  carbon  monoxide  is  the  last  constituent  to  be  deter- 
mined by  absorption.  Of  the  remaining  three,  two  must  be 
determined  by  an  explosion  and  the  third  by  difference. 

Make  a  careful  note  of  the  reading  of  the  burette  after  the 
CO  absorption,  as  this  figure  has  to  be  used  in  the  H2  and  CH4 
calculation. 

Turn  cock  (2)  so  as  to  give  connection  between  bottle  (7) 
and  burette,  cock  (3)  so  as  to  connect  (7)  through  burette 
(4)  and  bulb  (6)  with  (8).  Place  (8)  on  the  table  level  with 
(10)  and  hold  (7)  so  that  its  water-level  is  opposite  the  gradu- 
ation indicating  10  cubic  centimeters.  Now  open  cock  (i) 
carefully  and  allow  gas  to  pass  very  slowly  through  cocks  ( I ) 
and  (3)  into  the  storage  bulb  (6).  When  all  but  exactly  10 
cubic  centimeters  has  passed  into  the  bulb  (6)  close  cocks  (i) 
and  (3)  and  place  bottle  (7)  on  a  level  with  (10).  Pass  a 
little  water  from  (9)  directly  into  the  cup  (5)  so  as  to  get  all 
of  the  gas  out  of  the  passages  between  the  bulb  (6)  and  the  cup 
(5).  Also  open  cock  (i)  slightly  and  allow  water  to  pass 
from  cup  (5)  into  burette  to  zero  mark.  By  manipulating 
(7)  have  the  amount  of  gas  in  the  burette  exactly  10  cubic 
centimeters.  A  small  excess  may  be  gotten  rid  of  through 
cock  (i)  and  the  funnel  (5).  Turn  cock  (2)  so  as  to  connect 
burette  (4)  and  bottle  (10);  remove  funnel  (5)  and  connect 
oxygen  hose  to  top  capillary  tube.  Then  open  cock  (i)  and 
let  about  20  cubic  centimeters  of  oxygen  enter.  Remove  oxy- 
gen tubing  and  allow  about  10  cubic  centimeters  of  air  to  enter 
burette;  exact  proportion  of  oxygen  and  of  air  admitted  to 
burette  are  not  essential.  Close  cock  (i),  allow  water  to  pass 
from  (9)  through  (3)  and  (i)  into  cup  (5),  and  with  bottle 
(7)  lowered,  open  cock  (i)  until  water  passes  into  burette  to 
zero  mark.  Then  read  contents  of  the  burette  accurately. 
The  quantity  of  the  mixture  in  the  burette  should  be  in  the 
neighborhood  of  40  cubic  centimeters.  Attach  wires  to  the 
electrodes  on  the  sides  of  the  burette,  turn  cock  (2)  so  that  the 
burette  is  connected  to  the  bottle  (7),  see  that  tubing  is  straight 
and  cause  a  spark  to  pass  between  the  electrodes.  After  the 
explosion  allow  the  gases  to  stand  at  least  three  minutes  before 


102 


reading  the  burette.  Measure  the  contraction.  This  contrac- 
tion is  known  as  the  "ist  contraction."  Make  a  note  of  this, 
then  place  about  20  cubic  centimeters  of  potassium  hydrate 
solution  in  the  funnel  (5)  and  drain  the  burette.  Wash  with 
about  100  cubic  centimeters  of  air  saturated  distilled  water 
and  measure.  The  contraction  due  to  absorption  by  the  KOH 
solution  is  known  as  the  "2nd  contraction."  The  amount  of 
gas  left  after  the  absorption  for  CO,  divided  by  the  amount 
taken  for  the  explosion  is  called  the  "constant." 

The  amount  of  hydrogen  in  the  original  mixture  is  equal  to 
the  first  contraction  multiplied  by  two,  minus  four  times  the 
second  contraction  divided  by  three  and  multiplied  by  the 
constant. 

FORMULA  FOR  H2 
Per  cent,  by  vol.  of  H2  = 

2  X  (ist  contraction)  —  4  X  (2nd  contraction) 

—    X   constant. 
3 

Per  cent,  by  vol.  of  CH4  =  2nd  contraction  X  constant. 

The  constituent  which  we  call  "methane" — CH4 — often  con- 
tains in  addition  ethane — C2H6 — especially  in  rich  gases  and  in 
natural  gas  from  wells  which  are  approaching  exhaustion. 

The  ethane  present  is  burned  to  the  explosion  and  is  re- 
ported as  methane  increasing  the  per  cent,  of  methane  slightly, 
and  lowering  to  the  same  extent  the  percentage  of  hydrogen 
and  of  nitrogen. 

It  may,  however,  be  readily  determined  separately  if  it  is 
desired.  The  hydrogen  must  first  be  separately  absorbed  by 
means  of  a  palladium  tube.  This  is  done  by  adding  to  10  cubic 
centimeters  of  the  residual  gases  oxygen  and  air  just  as 
directed  above  for  explosion. 

The  palladium  tube  is  installed  between  the  burette  and  the 
storage  bulb.  A  beaker  containing  water,  which  is  kept  at  the 
boiling-point  by  a  Bunsen  lamp,  is  so  placed  as  to  have  the 
loop  of  the  tube  immersed  in  the  hot  water.  An  accurate 
reading  of  the  amount  of  mixture  is  then  taken  and  the  mixture 
passed  very  slowly  through  the  tube  into  the  storage  bulb  and 


103 

then  back.  Care  must  be  taken  not  to  pass  the  gas  through  the 
tube  too  rapidly,  or  the  heat  generated  is  apt  to  break  up  some 
of  the  methane.  The  palladium  does  not  really  absorb  the  hy- 
drogen from  the  mixture,  but  by  a  catalytic  action  causes  it 
to  combine  with  the  oxygen  present  and  form  water,  and  hence 
two-thirds  of  the  contraction  due  to  passage  of  the  mixture 
over  the  palladium  is  the  percentage  of  hydrogen.  The  known 
volume  of  mixture  after  the  hydrogen  absorption  is  then  ex- 
ploded and  the  contraction  noted. 

A  second  contraction  due  to  the  absorption  of  the  carbon 
dioxide  by  KOH  formed  is  also  noted. 

The  volume  of  the  methane  and  ethane  may  then  be  cal- 
culated from  the  following  formulae ; 

First  contraction,  due  to  condensation  of  water  formed,  and 

Second  contraction,  due  to  the  absorption  of  carbon  dioxide 
formed, 

Per  cent,  by  vol.  of  CH4  = 

4  X  (ist  contraction)  —  5  X  (2nd  contraction) 

X   constant. 

3 

Per  cent,  by  vol.  of  C2H6  = 

4  X  (2nd  contraction)  —  2  X  (ist  contraction) 

-   X  constant. 

O 

The  difference  between  the  sum  of  all  the  percentages  found 
by  the  above  determinations  and  100  is  the  percentage  of  nitro- 
gen. 

GENERAL  NOTES  FOR  ANY  TYPES  OF  APPARATUS. 
SOLUTIONS. 

i.  The  potassium  hydrate,  or  hydroxide  solution,  is  made  by 
dissolving  5  parts  by  weight  of  chemically  pure  potassium  hy- 
droxide (purified  sticks)  in  100  parts  by  weight  of  distilled 
water.  This  solution  should  be  kept  in  well  stoppered  bottles 
using  rubber  stoppers  to  prevent  sticking  and  deterioration  of 
solution  due  to  absorption  of  carbon  dioxide  from  the  air. 
The  same  hydrate  solution  is  used  for  the  absorption  of  CO2, 
of  bromine  fumes  and  with  the  pyrogallic  acid  for  oxygen,  and 


IO4 

of  CO2  after  methane.  The  hydroxide  which  comes  marked 
"Pure  by  Lime"  is  better  for  this  use  than  that  marked  "Pure 
by  Alcohol." 

2.  The  pyrogallic  acid  solution  is  made  by  dissolving   10 
parts  by  weight  of  chemically  pure  pyrogallic  acid  in  100  parts 
by  weight  of  the  above  hydrate  solution.     To  every  1,000  parts 
by  weight  of  this  solution  add  5  parts  by  weight  of  oxalic  acid 
as  a  preservative. 

Do  not  mix  the  pyrogallic  acid  solution  with  the  potassium 
hydrate  solution  except  in  the  funnel  and  until  quite  ready  for 
use,  as  the  potassium  pyrogallate  thus  formed  will  absorb 
oxygen  from  the  air  and  lose  its  strength.  At  least  two  min- 
utes should  be  given  the  oxygen  absorption  with  potassium 
pyrogallate  when  flue  gases  or  engine  exhaust  is  being  analyzed. 

3.  The  copper  monochloride  solution  is  made  by  dissolving 
75  parts  by  weight  of  chemically  pure  copper  monochloride 
in  720  parts  by  weight  of  concentrated  hydrochloric  acid,  to 
which  has  been  added  400  parts  by  weight  of  distilled  water. 
Ten  or  twenty  grains  or  more  of  clean  bare  copper  wire  or 
foil  should  be  added  and  kept  constantly  in  the  bottle  with  the' 
mixture  to  prevent  deterioration.     When  a  small  quantity  of 
the  solution  is  added  to  a  large  amount  of  water  a  cloudy 
white  precipitate  of  copper  monochloride  appears.     When  no 
cloudiness  is  thus  produced,  and  the  mixture  shows  a  blue 
tint,  the  preparation  has  become  oxidized  and  is  unreliable. 

4.  Gas-saturated  distilled  water  may  be  prepared  by  passing 
gas  through  the  water  at  a  temperature  not  less  than,  and 
preferably  a  few  degrees  above,  that  at  which  it  is  to  be  used 
so  as  to  avoid  evolution  of  the  dissolved  gases  in  the  burette. 

5.  Distilled  water  may  be  sufficiently  aerated  by  shaking  it 
vigorously  for  two  or  three  minutes  in  a  large  bottle  three- 
quarters  full  of  distilled  water. 

APPARATUS. 

6.  The  apparatus  may  be  cleaned  from  time  to  time  by  run- 
ning through  it  a  solution  of  potassium  bichromate  in  sul- 
phuric acid.    This  is  useful,  when  the  platinum  points  become 


coated  with  carbon.  This  cleaning  solution  should  be  used 
with  care,  as  sudden  mixing  of  the  sulphuric  acid  solution  with 
the  water  in  the  burette  generates  considerable  heat  which  may 
break  the  burette. 

7.  For  constant  use  it  is  well  to  install  the  water-jacketed 
burette  by  means  of  clamps  attached  to  a  permanent  pipe  stand 
supporting   shelf   over   a   sheet   lead   drain.     The   electrodes 
leading  from  burette  are  insulated  from  the  water-jacket  by 
rubber  tubing,  containing  copper  wires  fused  to  the  platinum 
leads  and  leading  to  the  terminals  of  a  %-inch  spark  coil, 
operated  by  at  least  two  ordinary  dry  batteries.    A  drain  fun- 
nel connected  by  rubber  tubing  to  a  glass  tube  of  ^-inch  bore 
extending  to  sink  or  drain  pipe,  will  be  found  of  great  con- 
venience in  a  permanent  installation  for  getting  rid  of  waste 
from  funnel  or  cup.    A  drain  tube  leading  from  bottom  of  the 
seal  bottle  upward  and  curved  in  a  semi-circle  at  the  top  so 
that  the  outlet  is  level  with  the  desired  water-level  in  the  bottle 
will  be  found  advantageous  in  securing  cleanliness. 

8.  Rubber  tubing  should  be  of  the  heavy- wall,  pure  gum 
variety,  and  of  such  internal  diameter  as  to  give  tight  joints 
over  the  glass  tubing,  etc.    The  joints  should  be  wired  to  in- 
sure freedom  from  leaks  incident  to  loosely  attached  tubing. 

9.  By  keeping  the  apparatus  and  all  of  the  bottles  filled  with 
water,  especially  when  not  in  use,  and  the  reagent  bottles  in 
immediate   proximity,    the    entire    outfit    acquires    about   the 
temperature  of  the  room,  and  the  error  arising  from  the  source 
of  temperature  in  the  sample  is  eliminated. 

10.  The  explosions  take  place  in  the  explosion  burette.     A 
coil  which  will  give  a  ^4 -inch  spark  is  ample.     Too  strong  a 
spark  is  apt  to  crack  the  glass  as  is  a  continuous  play  of  sparks 
between  the  points,  or  a  play  of  sparks  when  the  burette  is 
dry.    If  the  explosion  does  not  occur  simultaneously  with  the 
first  spark,  the  spark  need  not  be  continued.     Something  else 
is  wrong.     The  usual  trouble  is  that  the  confined  mixture  is 
not  an  explosive  one  and  the  proportion  of  air  or  oxygen  to 
gas  residual  must  be  changed. 

11.  The  reagent   funnel  and  top  ground  joint  of  burette 


io6 

should  be  washed  well  after  the  completion  of  each  analysis 
to  prevent  sticking  at  the  ground  joint,  due  to  any  potassium 
hydrate  solution  which  may  be  present.  This  rule  is  applicable 
also  to  other  movable  parts  such  as  cocks  which  are  likely  to 
stick. 

12.  The  bulb  which  is  not  graduated,  or  an  extra  pipette  is 
used  to  hold  the  excess  of  gas  when  the  explosion  is  being 
made.    The  analyst  occasionally  loses  an  explosion,  and  were 
it  not  for  the  gas  thus  held,  the  entire  analysis  would  have  to  be 
made  over.     By  putting  into  the  bulb  all  of  the  gas  that  is 
left  after  the  CO  absorption,  except  the  10  cubic  centimeters 
which  is  used  for  the  explosion,  several  explosions  may  be 
made  as  checks  on  one  another,  or  in  case  the  first  one  is  lost. 

13.  If  the  cocks  stick,  they  can  usually  be  loosened  by  a 
little  hot  water  on  the  outside.     They  should  be  kept  well  lu- 
bricated with  a  mixture  of  equal  parts  of  vaseline,  tallow  and 
paraffme. 

14.  For  getting  samples,  it  is  best  to  get  four  sample  cans. 
The  sketch  above  will  show  what  these  are.     In  getting  the 
sample  the  can  is  placed  in  an  upright  position  and  filled  quite 
full  of  water,  perfectly  saturated  with  the  gas  to  be  sampled 
in  order  to  expel  all  of  the  air.     A  tube  connected  with  the 
upper  stop-cock  is  then  introduced  into  the  space  from  which 
the  gas  sample  is  to  be  drawn,  and  the  lower  stop-cock  is 
opened,  allowing  the  water  to  run  out  and  thus  the  sample 
is  aspirated  into  the  can. 

In  drawing  samples  from  places  which  have  a  suction  in- 
stead of  a  pressure,  such  as  the  inlet  of  an  exhauster,  or  at 
the  base  of  a  stack,  or  in  the  breeching  of  a  boiler,  the  water 
should  be  allowed  to  flow  through  a  U-shaped  glass  tube 
attached  by  a  piece  of  rubber  hose  to  the  lower  stop-cock.  If 
this  is  not  done,  after  the  water  is  all  out,  air  will  enter  and 
spoil  the  sample.  It  is  essential  to  draw  out  all  of  the  water, 
even  if  only  a  small  sample  is  required,  as  a  number  of  the 
constituents,  illuminants  and  CO2,  for  example,  are  soluble  in 
water.  If  the  gas  to  be  sampled  is  under  pressure  it  is  well 


enough  to  allow  it  to  flow  through  the  can  for  a  few  seconds 
after  all  of  the  water  has  run  out. 

To  get  the  sample  out  of  the  can,  the  lower  stop-cock  is 
connected  by  a  hose  with  a  source  of  water  under  pressure 
such  as  an  aspirator  bottle  filled  with  water  and  placed  at  a 
level  above  that  of  the  sampling  can,  and  as  the  water  runs 
into  the  can  the  gas  will  be  displaced  and  may  be  led  by  means 
of  a  hose  to  the  burette. 

15.  The  principal  precaution  necessary  in  gas  analysis  is  to 
see  that  the  temperature  of  the  apparatus  and  of  the  water 
used,  and  of  any  additional  water  which  may  be  used  as  well 
as  the  temperature  of  the  sample  undergoing  examination,  does 
not  change  during  the  analysis.     A  change  of  5.2°  F.  will 
cause  a  change  of  about  I  per  cent,  in  the  volume  of  any  gas 
at  an  ordinary  temperature  of  60°  F.     The  temperature  at 
which  an  analysis  is  made  is  immaterial  but  that  temperature 
MUST  remain  constant. 

16.  In  reading  the  burette,  hold  levelling  bottle  front  and 
just  to  one  side  of  the  burette,  so  that  the  eye  of  the  analyst 
can  sight  along  the  under  surface  of  the  water-level  and  bring 
it  in  the  same  horizontal  plane  with  the  bottom  of  the  meniscus 
in  the  burette. 

Analysis. — The  quantities  of  reagents  and  wash  water  d£- 
scribed  in  the  foregoing  method  of  analysis  are  intended  main- 
ly for  the  analysis  of  carbureted  water-gas,  henc^n  the  analy- 
sis of  any  other  gas  the  quantities  specified  should  be  changed 
if  it  is  found  to  be  necessary  in  order  to  insure  complete  ab- 
sorption of  the  various  constituents.  This  is  also  true  of  the 
oxygen  and  air  required  for  explosion. 

1 8.  Introduce  potassium  hydrate  solution  slowly   for  first 
absorption  as  the  tendency  otherwise  is  to  secure  too  high  a 
percentage  for  the  carbon  dioxide. 

19.  Care  should  be  taken  in  handling  bromine.    Keep  it  al- 
ways under  water,  and  do  not  allow  it  to  come  in  contact  with 
the  skin.     Bromine  is  an  exceedingly  energetic  reagent  and 
will   cause  painful   chemical  burns.     If   bromine   fumes   are 
breathed,  relief  from  the  irritation  caused  to  the  throat  can  be 


loS 


obtained  by  inhaling  alcohol  or  steam.  The  slick  feeling  caused 
by  getting  potassium  hydrate  on  the  hands  may  be  removed  by 
a  little  dilute  hydrochloric  acid. 

20.  The  absorption  of  illuminants  by  bromine  is  a  heat  pro- 
ducing reaction,  and  the  increased  temperature  is  apt  to  cause 
the  sample  to  expand  unduly  and  may  cause  the  loss  of  a  part 
of  the  sample  by  forcing  it  out  through  the  cock  and  thus 
vitiate  the  analysis.    If  it  is  seen  that  the  expansion  is  becom- 
ing excessive  a  little  water  may  be  added.     The  bulb  at  the 
lower  end  of  the  Morehead  burette  is  provided  for  this  con- 
tingency.    In  the  analysis  of  acetylene,  which  contains  over 
90  per  cent,  of  illuminants,  this  is  especially  apt  to  occur.     If 
the  percentage  of  illuminants  is  high,  it  is  well  to  admit  a 
little  water  during  the  absorption  with  bromine  to  restore  the 
normal  temperature  of  the  gas. 

21.  Twenty  cubic  centimeters  of  potassium  pyrogallate  solu- 
tion when  mixed  with  20  cubic  centimeters  of  potassium  hy- 
drate solution  produce  a  rise  in  the  temperature  of  the  mix- 
ture of  about  5°  F.  over  that  of  the  original  solutions.    The 
heat  gained  by  the  gas  in  the  burette  due  to  this  cause  should, 
be  taken  into   consideration  and  sufficient  time  allowed  the 
burette  gases  to  resume  initial  temperature  before  reading, 
^his  solution  should  be  passed  into  the  burette  very  slowly,  as 
the  absorption  of  oxygen  is  rather  sluggish.     The  absorption 
may  be  cor^kiered  complete  when  no  further  discoloration  to 
purple  or  brown  occurs  upon  introduction  of  the  clear  reagent. 

22.  The  absorption  of  the  last  traces  of  CO  is  attended  with 
difficulty,   and  hence   the  analyst   should   be   careful   to   add 
sufficient  copper  monochloride  solution  and  allow  plenty  of 
time  for  the  complete  absorption.    The  reagent  being  strongly 
acid,  about  10  cubic  centimeters  of  potassium  hydrate  solution 
should  always  be  added,  after  passing  in  about  50  cubic  centi- 
meters of  wash  water  to  insure  removal  of  all  fumes  of  hydro- 
chloric acid  and  followed  with  the  customary  wash  water. 

23.  When  carbureted  water-gas  is  being  analyzed,  double 
quantities  of  residual  gases,  oxygen  and  air  may  be  taken  for 
the  explosion  in  order  to  secure  higher  accuracy. 


109 

24.  Prior  to  all  explosions,  sufficient  time  (at  least  two  min- 
utes)  should  be  allowed  for  the  gases  to  thoroughly  diffuse 
through  the  oxygen  and  air  added  so  as  to  give  a  homogeneous 
explosive  mixture  and  insure  the  combustion  of  all  the  oxidi- 
zable  gases. 

25.  No  special  care  need  be  taken  in  measuring  the  amount 
of   air,   or  of   oxygen  added   for  the  explosion,   though  the 
amounts  taken  should  not  be  less  than  those  stated  in  the 
"Method."     Care  must  be  taken,  however,  to  measure  accu- 
rately the  amount  of  gas  taken  for  the  explosion,  and  the  total 
amount  of  the  gas,  air  and  oxygen  just  before  the  explosion. 

26.  Air  is  added  to  the  mixture  to  be  exploded  merely  to 
lessen  the  jar. 

If  the  gas  is  very  poor,  or  contains  large  quantities  of  nitro- 
gen, no  air  need  be  added,  and  on  the  other  hand  if  the  gas  is 
quite  rich,  no  oxygen  need  be  added,  air  being  sufficient,  al- 
though if  oxygen  is  available  it  is  best  added  to  insure  combus- 
tion. With  extremely  poor  gas  such  as  blast-furnace  gas  and 
the  like,  no  explosion  will  take  place  even  when  oxygen  is  used 
and  no  air  added.  Oxyhydrogen  gas  may  be  necessary,  in 
such  cases.  This  is  made  by  the  electrolysis  of  water  slightly 
acidulated  with  sulphuric  acid.  Five  to  ten  cubic  centimeters 
of  the  oxygen  and  hydrogen  mixture  added  in  addition  to  the 
oxygen  will  always  insure  an  explosion.  As  it  recombines  to 
water,  no  special  reading  or  note  of  the  volume  added  need 
be  made. 

27.  Use  only  C.  P.  chemicals. 

28.  Never  allow  the  funnel  to  become  entirely  empty;  al- 
ways keep  about  j^-inch  of  water  or  other  liquid  in  the  bottom 
to  prevent  the  suction  of  air  into  the  burette. 

29.  In  acetylene,  flue  gas,  engine  exhaust,  air  and  gasoline 
gas,  there  is  no  hydrogen  or  methane,  and  hence  the  analysis 
need  not  be  carried  beyond  the  absorption  with  copper  mono- 
chloride  for  CO,  and  the  oxygen  tank  or  apparatus,  the  elec- 
tric coil,  batteries,  etc.,  need  not  be  provided.     In  analyses  of 
these  gases  the  sum  of  the  first  found  contractions  subtracted 
from  100  gives  the  percentage  of  nitrogen. 

8 


no 


30.  Where  analyses  are  to  be  made,  or  where  dispatch  is  an 
important  element,  it  will  be  more  satisfactory  to  obtain  a 
cylinder  of  compressed  oxygen  for  use  in  the  hydrogen  and 
methane   determinations,   but  where   the  apparatus   is   to   be 
moved  from  place  to  place,  or  is  to  be  used  only  occasionally, 
or  where  the  analyses  are  confined  for  the  most  part  to  gases 
which  do  not  contain  hydrogen  or  methane,  such  as  flue  gases, 
acetylene,  air,  engine  exhaust,  etc.,  a  cheaper  and  quite  satis- 
factory substitute  can  be  had  in  a  small  retort  by  means  of 
which  oxygen  can  be  generated  on  the  spot  as  needed. 

To  generate  oxygen  this  retort  is  filled  not  more  than  half 
full  with  a  pulverized  thoroughly  mixed  charge  of  potassium 
chlorate  and  manganese  dioxide  in  the  proportions  of  20  of 
the  first  to  i  of  the  latter  by  weight.  This  is  heated  gently 
over  a  Bunsen  lamp.  The  evolution  of  oxygen  begins  at  once 
and  it  may  be  led  to  the  burette  by  means  of  a  rubber  tube. 
As  100  grams  of  potassium  chlorate  will  produce  27,000  cubic 
centimeters  of  oxygen  and  only  about  20  cubic  centimeters  of 
oxygen  are  used  for  one  analysis,  a  very  small  spoonful  of  the 
mixture  will  suffice  for  a  great  many  explosions. 

31.  The  method  of  analysis  is  so  laid  out  that  each  deter- 
mination must  be  made  in  its  turn.     With  the  exception  of 
the  absorption  of  CO2  with  KOH,  and  possibly  that  of  CO 
with  cuprous  chloride,  no  isolated  determination  of  any  one 
constituent  can  be  made  with  anything  approaching  accuracy 
without  starting  at  the  beginning  and  making  all  of  the  ab- 
sorptions down  to  that  constituent. 

Careful  readings  of  the  burette  should  be  taken  before  and 
after  each  determination,  and  especial  care  should  be  taken  in 
making  the  analysis  to  thoroughly  absorb  each  constituent  in 
its  turn.  Partial  absorption,  or  errors  in  the  readings,  will 
not  only  introduce  an  error  in  the  percentages  of  the  constit- 
uents in  question,  but  the  remaining  portions  of  this  constit- 
uent will  effect  the  latter  determinations  in  the  analysis  and 
thus  have  a  doubly  vitiating  effect  upon  the  accuracy. 

Any  CO2  left  after  the  first  absorption  will  be  absorbed  by 
the  KOH  following  the  bromine  and  will  be  reported  as  illu- 


Ill 


minant  or  if  by  chance  it  is  not  absorbed  by  the  KOH  follow- 
ing the  bromine,  it  will  be  absorbed  by  the  alkaline  pyrogal- 
late  solution  used  for  oxygen  absorption  and  will  appear  as  O2. 

Any  illuminant  not  absorbed  will  remain  and  burn  to  ap- 
proximately 3^  times  its  volume  of  CO2  when  the  explosion 
is  made  and  will  appear  as  CH4.  A  very  small  proportion  of 
illuminant  left  and  burned  and  calculated  to  CH4  will  be 
sufficient  to  run  the  total  of  the  analysis  to  more  than  100 
per  cent.  Any  bromine  vapors  left  after  the  absorption  with 
bromine  will  be  absorbed  by  the  pyrogallate  solution  and  will 
be  reported  as  Oe. 

Any  unabsorbed  CO  will  be  burned  to  CO2  in  the  explosion, 
H2  and  CH4,  and  increase  the  percentage  of  N2  to  the  same 
extent. 

Any  unabsorbed  O2  left  would  decrease  the  percentage  of 
H2  and  CH4,  and  increase  the  percentage  of  N2  to  the  same 
extent. 

Any  unabsorbed  CO2  after  the  explosion  will  decrease  the 
percentage  of  CH4  and  increase  that  of  the  H2  and  N2. 

The  N2  being  determined  by  difference  will  necessarily  show 
the  net  effect  of  any  and  all  errors  in  either  readings  of  the 
burette,  or  in  the  performance  of  the  analysis. 

Specific  Gravity  of  Gas. 

Schilling's  apparatus  for  ascertaining  the  specific  gravity,  or 
density,  of  gases,  is  both  simple  and  convenient. 

It  consists  of  a  glass  jar  with  a  metal  top  into  which  fits  a 
brass  column  having  suspended  from  its  base  a  long  graduated 
glass  tube  and  at  its  top  a  cock  and  a  ground  joint  socket,  into 
which  sets  a  socket  holding  a  small  glass  tip  closed  in  at  the 
top  with  a  very  thin  piece  of  platinum.  In  this  platinum  is  a 
very  small  hole  to  permit  the  passage  of  gas  or  air  at  a  very 
slow  rate.  All  metal  parts  are  nickeled. 

The  mode  of  operation  is  as  follows :  The  glass  jar  is  filled 
with  water  to  or  a  little  above  the  top  graduation  of  the  tube. 
The  tube  is  then  withdrawn  so  as  to  fill  it  with  air.  The 
cock  on  the  standard  is  then  closed  and  the  tube  replaced  in 


112 


the  jar.  The  cock  is  then  opened  and  with  a  stop  watch  the 
time  is  taken  that  elapses  while  the  water  passes  from  the 
lowest  graduation  to  the  top  or  the  next  to  the  top  graduation. 


FIG.  24. 

The  tube  is  then  withdrawn  and  filled  with  gas  and  the 
procedure  repeated  the  same  as  with  air. 

The  specific  gravity,  air  being  one,  is  obtained  by  dividing 
the  gas  time  squared  by  the  air  time  squared. 

Heating  Value  of  Gas. 
(From  Report  of  American  Gas  Institute.) 

Set  up  the  apparatus  as  shown  in  cuts  of  the  different  sets. 
Screw  on  the  inlet  water  pipe  and  see  that  the  air  vent  tube 
is  in  its  place  in  this  pipe. 


FIG.  25. 


Level  the  calorimeter  by  means  of  the  screw  feet  and  plumb- 
bob. 

Connect  the  center  hose  nipple  on  the  inlet  weir  with  rubber 
tubing  to  the  water  supply  and  the  side  connection  to  the  sink 
to  carry  away  the  overflow. 

Connect  the  tubing  for  water  running  to  weighing  pail  to  the 
vertical  nipple  on  the  three-way  cock  on  the  outlet  weir  and 
for  the  wasteyto  the  side  nipple. 


FIG.  26. 

Handle  the  thermometers  with  the  greatest  of  care. 

Screw  the  32°  to  100°  thermometer  on  the  inlet  water  pipe 
and  the  60°  to  110°  thermometer  on  the  top  of  the  instrument 
for  the  outlet  water.  Screw  the  small  thermometer  in  place 
on  the  exhaust  flue. 

Place  the  two  telescopic  sights  in  position  on  the  water 
thermometers,  being  very  careful  not  to  break  them  off  by 
pressure  against  the  sights. 

Connect  the  meter  to  the  governor  and  the  governor  to  the 


H5 

burner  with  short  pieces  of  rubber  tubing,  or  with  flexible 
metal  tubing  having  coupled  ends. 

The  calorimeter  should  be  set  up  in  a  quiet,  light  and  well 
ventilated  room  or  cabinet,  which  is  free  from  draughts  and 
in  which  the  temperature  can  be  maintained  constantly  at  not 
less  than  6o°F.  The  room  should  be  provided  with  a  sink  and 
with  a  good  supply  of  running  water.  It  is  advisable  to  have  a 
large  shallow  overhead  covered  tank,  from  which  the  water 
supply  can  be  taken.  Should  the  tank  capacity  be  small  and 
not  hold  enough  water  for  a  prolonged  series  of  readings,  a 
small  gas  water  heater  may  be  employed  as  already  noted  to 
bring  the  water  to  approximately  the  room  temperature.  It 
is  desirable  to  use  water  that  is  clear  and  free  from  sus- 
pended matter  in  the  calorimeter,  therefore,  a  filter  should  be 
installed  in  the  water  supply  line  before  it  enters  the  overhead 
tank. 

If  only  a  single  test  is  desired,  gas  may  be  taken  from  the 
house  piping,  but  if  an  average  value  is  required,  a  small  gas 
holder,  or  averaging  tank,  should  be  used,  and  the  gas  flowing 
into  the  holder  adjusted  to  a  rate  of  flow  to  just  fill  it  in  the 
time  during  which  the  sample  is  to  be  taken.  Care  should  be 
taken  to  have  a  short  service  to  this  holder  in  order  that  an 
average  sample  of  gas  may  be  obtained,  and  if  the  sample  be 
taken  from  a  line  on  which  there  is  no  considerable  consump- 
tion, see  that  this  line  is  thoroughly  purged  before  sampling. 
It  is  recommended  that  the  gas  be  metered  at  a  pressure  not 
to  exceed  two  inches  of  water;  if  this  is  not  obtainable,  it  is 
advisable  to  insert  a  holder  or  diaphragm  governor  in  the 
supply  line  to  reduce  the  pressure  to  within  this  limit. 

Set  up  the  calorimeter  so  that  the  overflow  and  outlet  water 
can  be  easily  led  to  the  sink.  Make  water  connections  with 
rubber  tubing,  being  careful  not  to  cramp  the  tubing.  To 
avoid  air  currents  caused  by  the  movement  of  the  observer's 
body,  set  up  the  calorimeter  so  that  the  water  supply  and  waste 
may  be  easily  adjusted  and  that  all  temperatures  may  be  readily 
observed.  Lead  the  outlet  water  to  a  waste  funnel  supported 
a  little  above  the  top  of  the  copper  or  glass  container  used  in 


n6 

collecting  the  water,  so  that  the  water  can  be  shifted  from  the 
funnel  to  the  container  and  back  without  spilling. 

Set  up  the  gas  meter  facing  the  observer  and  level  it  care- 
fully. Then  adjust  the  water-level  of  the  meter,  both  inlet  and 
outlet  being  open  to  the  air.  To  do  this,  remove  the  plug  from 
the  dry  well,  open  the  funnel  cock  and  disconnect  the  tubing  on 
the  outlet  of  the  meter.  Add  or  remove  water  (through  the 
funnel  or  by  the  cock  under  the  gauge  glass)  until  the  lowest 
edge  of  the  meniscus  just  touches  the  scratch  on  the  gauge 
glass,  or  is  even  with  the  fixed  pointer.  If  the  meter  has  been 
filled  with  fresh  water  the  gas  must  be  allowed  to  burn  at 
least  two  hours  before  making  a  test.  When  the  water  in  the 
meter  is  saturated  with  gas,  20  minutes  should  be  sufficient. 

Fill  pressure  regulator  with  water,  about  ^  full,  then  con- 
nect it  to  the  calorimeter  burner.  Metallic  tubing  is  prefer- 
able, but  when  rubber  tubing  is  used  to  connect  meter,  pressure 
regulator  and  burner,  connections  should  be  as  short  as  pos- 
sible, and  should  be  saturated  with  the  gas. 

Turn  on  gas  and  allow  it  to  burn  for  5  to  10  minutes  with 
the  burner  on  the  table.  Shut  off  gas  at  burner  and  watch 
hand  on  meter  for  leakage.  Be  sure  that  all  leaks  are  stopped 
before  attempting  to  make  a  test.  Start  water  running  through 
the  calorimeter  at  a  rate  of  about  3  pounds  per  minute.  Then 
regulate  the  gas  to  flow  at  the  rate  of  4  to  7  feet  an  hour,  as  may 
be  found  by  experiment  to  give  the  highest  result  with  the  gas 
to  be  tested,  admitting  enough  air  through  the  burner  so  that 
the  flame  shows  a  faint  luminous  tip,  then  insert  the  burner  as 
far  up  into  the  combustion  chamber  as  the  bracket  permits, 
and  observe  again  the  condition  of  the  flame  to  see  that  it  is 
all  right,  using  a  mirror. 

The  excess  of  air  passing  through  the  calorimeter  is  con- 
trolled somewhat  by  the  position  of  the  damper  in  the  exhaust 
port,  and  the  best  results  are  obtained  by  having  the  excess  air 
as  low  as  possible  and  still  maintaining  complete  combustion  of 
the  gas.  To  determine  this  position  of  the  damper,  some  ex- 
perimentation may  be  necessary.  Operate  the  calorimeter 
until  a  thermal  balance  is  established  on  the  inlet  and  outlet 


water  thermometers.  Start  with  the  damper  closed,  then  open 
slightly,  observing  carefully  the  outlet  thermometer.  When 
this  thermometer  reads  at  a  maximum — or  in  other  words, 
when  the  greatest  rise  in  temperature  is  given  to  the  water, 
which  is  presumably  passing  through  the  calorimeter  uni- 
formly— the  damper  is  in  approximately  the  correct  position 
for  the  amount  of  gas  being  burned,  and  the  excess  air  neces- 
sary for  perfect  combustion  is  at  a  minimum. 

Water  should  be  regulated  so  that  there  is  a  difference  be- 
tween the  inlet  and  outlet  temperatures  of  about  15°  F.  The 
temperature  of  the  inlet  water  should  vary  but  little  when  an 
overhead  tank  is  used  and  the  water  maintained  at  room  tem- 
perature. Be  sure  that  both  overflows  are  running. 

Before  making  the  test,  the  barometer,  temperature  of  the 
gas  at  the  meter,  temperature  of  room  and  temperature  of 
exhaust  products  should  be  recorded.  It  is  desirable  to  have 
the  temperature  of  the  inlet  water  and  temperature  of  exhaust 
products  as  nearly  as  possible  at  room  temperature,  in  order  to 
establish  more  nearly  a  thermal  balance — the  difference  in  these 
temperatures  should  never,  exceed  5°. 

Next  allow  the  gas  to  burn  in  the  calorimeter  until  a  ther- 
mal balance  is  established,  or  until  there  is  the  least  change 
in  the  inlet  and  outlet  waters. 

The  test  may  now  be  started  by  shifting  the  outlet  water 
from  the  funnel  to  the  container  just  as  the  large  hand  on  the 
meter  passes  the  zero  point.  Readings  are  then  made  of  inlet 
and  outlet  thermometers,  making  the  readings  as  rapidly  as  the 
observer  is  able  to  record  them  during  the  consumption,  prefer- 
ably of  two-tenths  of  a  cubic  foot  of  gas.  At  least  ten  readings 
should  be  made  of  both  inlet  and  outlet  water  temperatures. 
Water  is  again  shifted  from  the  container  to  the  waste  funnel 
as  the  hand  passes  the  zero  point  the  second  time.  Water  is 
then  weighed  or  measured.  The  uncorrected  heating  value 
per  cubic  foot  is  obtained  by  multiplying  the  difference  of  the 
averages  of  inlet  and  outlet  temperatures,  by  the  number  of 
pounds  of  water  and  by  dividing  by  two-tenths.  This  quantity 
is  divided  by  the  correction  factor  for  barometer  and  tempera- 


n8 


ture,  obtainable  from  tables,  to  give  the  heating  value  at  30 
inches  pressure  and  60°  F.  The  weight  or  contents  of  con- 
tainer should  be  obtained  while  the  inside  is  wet.  This  may  be 
done  by  rilling  it  with  water,  emptying  and  shaking  for  about 
five  seconds  in  an  inverted  position.  This  will  do  away  with 
any  correction  where  several  consecutive  tests  are  required 
with  same  container. 

A  second,  and  perhaps  a  third  test  is  advisable,  and  these 
should  be  made  without  disturbing  the  existing  conditions, 
provided  all  readings  are  within  the  above  prescribed  limits. 
In  practice  the  operator  should  get  consecutive  results  on  the 
same  holder  of  gas  within  ten  (10)  B.  t.  u/s.  Under  such 
conditions  an  average  of  the  results  may  safely  be  taken. 

RESULTS  AS  OBTAINED  BY  CALCULATION. 

The  method  of  calculating  the  calorific  value  of  the  gas 
from  the  observations  indicated  is  very  simple  when  all  read- 
ings are  made  in  English  units,  as  recommended,  and  entered 
in  some  form  conveniently  arranged.  A  simple  record  sheet 
is  shown  herewith,  a  convenient  size  for  which  is  5  by  8  inches. 

The  averages  of  the  inlet  and  outlet  water  temperatures  are 
determined  and  necessary  corrections  for  thermometer  errors 
are  made.  The  difference  in  these  averages  should  give  the 
rise  in  temperature  of  the  water.  This  rise  in  temperature  of 
the  water  is  therf  multiplied  by  the  number  of  pounds  of  water 
passed  through  the  calorimeter  during  the  test. 

The  product  of  these  two  is  then  divided  by  the  quantity 
of  gas  burned — 0.2  of  a  cubic  foot.  This  quotient  will  give  the 
heating  value  of  one  cubic  foot  of  gas  in  B.  t.  u.'s  at  the  in- 
dicated temperature  and  barometric  pressure.  To  correct  this 
to  60°  F.  and  30  inches  pressure,  divide  by  the  "Correction 
Factor"  for  the  indicated  temperature,  and  pressure  as  ob- 
tained from  some  standard  table.  [Printed  on  card  sent  with 
apparatus.]  The  final  result  will  be  the  corrected  heating 
value  of  the  gas  tested,  in  B.  t.  u.'s. 


H9 

Expressing  the  above  in  a  formula  we  have : 

W  X  T 
B.  t.  u.'s  per  cubic  foot  =     — — . 

W  =  weight,  in  pounds,  of  water  passed. 

T  =  the  average  difference  in  temperature,  in  degrees 

Fahrenheit,  between  inlet  and  outlet  water. 
G  =  corrected  volume  of  gas  burned,  in  cubic  feet. 
The  correction  for  atmospheric  humidity  is  made,  finally,  if 
so  desired. 

USE  OF  COMPUTER. 

The  labor  of  making  the  calculations  for  determining  the 
heating  value  from  observations  of  a  calorimeter  may  be 
lessened  by  the  use  of  a  heating  value  computer.  The  computer 
consists  of  a  circular  slide  rule,  with  divisions  corresponding  to 
the  readings  made  on  the  calorimeter.  This  computer  gives 
the  corrected  heating  value  of  a  cubic  foot  of  gas  in  B.  t.  u.'s, 
having  the  barometric  pressure  and  temperature  of  the  metered 
gas,  and  the  difference  in  temperature  between  the  inlet  and 
outlet  water,  and  the  pounds  of  water  passed.  This  computer 
is  designed  to  operate  within  the  limits  of  from  300  to  800 
B.  t.  u.'s.  Should  a  gas  of  a  lower  or  higher  heating  value  be 
measured,  the  computer  can  still  be  used  by  dividing  or  multi- 
plying one  or  the  other  of  the  factors  in  its  computation.  A 
cut  of  this  computer  can  be  found  on  page  373,  Vol.  Ill,  Pro- 
ceedings of  the  American  Gas  Institute. 

Corrections  for  Atmospheric  Humidity. 
(From  Report  of  American  Gas  Institute.') 

This  correction  is  found  to  be  the  greatest  when  the  per- 
centage of  humidity  of  the  atmosphere  is  the  lowest.  The 
reason  being  that  the  relatively  dry  air  entering  the  calorimeter 
causes  to  be  carried  out  in  the  exhaust  products  a  larger 
amount  of  the  water  in  the  form  of  a  gas  or  vapor,  that  is 
formed  by  the  combustion  of  the  gas,  and  which  does  not 
condense,  and,  therefore  does  not  give  up  its  latent  heat  to  the 
calorimeter. 


I2O 

The  humidity  correction  should  correct  for  any  discrepancy 
in  water  vapor  carried  in  by  the  air  and  gas,  compared  with 
that  carried  out  by  the  products  of  combustion. 

Owing  to  the  contraction  in  volume,  during  the  combustion 
of  ordinary  illuminating  gas  and  air,  this  discrepancy  is  prac- 
tically nothing  when  the  percentage  of  atmospheric  humidity  is 
about  80  per  cent.,  at  normal  temperatures,  and  the  excess  of 
air  introduced  for  combustion  is  about  30  per  cent. 

In  correcting  for  atmospheric  humidity  it  is  assumed  that 
the  gas  is  saturated  with  water  vapors — having  passed  through 
a  wet  meter.  This  assumption  might  not  be  absolutely  true, 
but  the  percentage  of  saturation  has  been  found  always  to  be 
high,  and  as  the  volume  of  gas  is  only  about  one-eighth  of  the 
mixture,  the  error  involved  may  be  neglected. 

TABLE  I.— CORRECTIONS  TO  OBSERVED  HEAT  TO  GET  TOTAI,  HEAT 
VAUTE.    AIR,  GAS  AND  EXHAUST  MUST  BE  AT 

THE  SAME  TEMPERATURE. 
If  7  volumes  of  air  per  volume  of  gas  are  used. 

Humidity  Room  temperatures 

Per  cent.  65°  70°  75°  80°  85°  90° 

10  +4.8  +5.7  +6.7  +7.9  +9.2  +10.5 

20  +4.1  +4.9  +5.7  +6.8  4-7.8  4-  9.0 

30  4-3.4  4-4.1  +4.7  4-5.6  4-6.5  4-  74 

40  4-2.7  4-3.2  4-3.7  +4.5  4-5.2  4-  5.9 

50  4-2.0  4-2.4  4-2.8  +3.4  4-3.8  4-  4.3 

60  4-1.3  4-1.6  +1.8  +2.2  +2.5  +  2.8 

70  +0.6  +0.8  +0.8  +1.0  -+I.2  +1.2 

80  —o.i  +0.0  —o.i  —o.i  —o.i  -  0.3 

oo  —0.8  —0.9  —i.i  —1.3  —1.5  —  1.9 

100  — 1.6  — 1.8  — 2.0  —2.4  — 2.8  —  3.4 

Note — These  corrections  are  expressed  in  B.  t.  u. 

Directions  for  Using  Or  sat  Apparatus. 

The  gas  burette  A  (in  Fig.  27)  is  attached  to  the  levelling 
flask  B,  which  is  filled  with  water.  By  raising  B,  A  is  filled 
with  water  to  the  uppermost  mark.  In  order  thus  to  fill  A 
with  water,  the  air  must  have  opportunity  to  escape  from  the 
uppermost  portion  of  A. 

The  absorption  pipette  D  is  used  to  absorb  carbonic  acid  gas. 


121 


It  contains  such  a  quantity  of  caustic  potash  solution  that  when 
the  solution  is  drawn  entirely  into  the  front  part  of  the  pipette 
(the  proper  position  for  the  solution  when  the  pipette  is  ready 
for  use),  the  front  part  of  the  pipette  is  filled  with  the  solution, 


FIG.  27. 


and  the  rear  part  is  empty.  The  solution  is  drawn  up  into  the 
front  part  of  the  pipette  D,  as  follows :  Communication  is  es- 
tablished with  the  outside  air  by  means  of  the  stop-cock  a. 
Stop-cock  d,  e  and  /  are  closed.  A  is  filled  with  water  by  rais- 


122 


ing  B.  Stop-cock  a  is  closed,  stop-cock  d  is  opened,  and  the 
solution  in  pipette  D  is  drawn  into  the  front  part  of  the  pipette, 
by  lowering  B.  When  the  solution  has  filled  the  front  part  of 
D,  close  stop-cock  d. 

Rubber  bags  are  usually  attached  to  the  capillary  opening  at 
the  rear  of  the  pipettes  to  prevent  free  access  of  air  and  to 
allow  the  escape  of  the  confined  air  when  the  solution  is  per- 
mitted to  flow  back  again  in  the  pipette  after  having  been  used. 

Pipette  B  is  for  the  absorption  of  oxygen  gas,  and  pipette  F 
for  the  absorption  of  carbon  monoxide  gas.  Pipette  B  is  filled 
similar  to  D,  with  a  solution  of  pyrogallic  acid  or  with  thin 
sticks  of  phosphorus  in  water.  In  case  the  phosphorus  is  used, 
the  pipette  is  covered  with  black  paper  to  prevent  the  action 
of  light  on  the  phosphorus.  Just  as  in  the  case  of  D,  before 
using  H  and  F,  the  solutions  are  drawn  into  the  front  parts  of 
the  respective  pipettes,  and  held  there  by  closing  their  respec- 
tive cocks.  Pipette  F  contains  a  solution  of  cuprous  chloride. 
The  front  part  of  each  of  the  pipettes  contains  a  bundle  of 
glass  tubes,  in  order  to  increase  the  absorption  power  of  the 
pipettes.  The  glass  tubes  for  pipette  F  contain  curved  copper 
wires  to  maintain  the  cuprous  chloride  solution  at  a  constant 
strength. 

The  pipettes  being  in  readiness  with  stop-cocks  d,  e  and  / 
closed,  and  A  open,  burette  (A)  is  filled  with  water  by  raising 
(B).  The  other  end  of  the  capillary  tube  or  beam  is  now  con- 
nected with  the  gas  to  be  tested.  A  bent  tube  is  provided  for 
purifying  the  gas  before  allowing  it  to  pass  into  the  apparatus. 
This  tube  is  fastened  outside  the  case  on  the  upper  left  side, 
and  is  connected  with  the  capillary  stop-cock  tube  by  means  of 
rubber  tubing.  Before  attaching  the  bent  tube  it  is  filled  with 
a  sufficient  quantity  of  calcium  chloride,  or  glass  wool.  When 
everything  is  ready,  with  a  connection  made  for  the  gas  to 
enter  the  apparatus  through  the  bent  tube,  (B)  is  lowered,  by 
which  means  the  gas  is  drawn  into  A  to  the  O  mark.  Par- 
ticular care  must  be  taken  that  there  is  exactly  100  cubic  cen- 
timeters of  the  gas.  Stop-cock  A  is  now  closed,  stop-cock  D 
opened,  vessel  (B)  raised,  burette  (A)  filled  with  water,  and 


123 

the  100  cubic  centimeters  of  gas  forced  into  the  pipette  D. 
Here  it  is  allowed  to  stay  for  some  minutes,  the  pipette  being 
shaken  slightly,  if  practicable,  in  order  to  bring  the  gas  fully 
into  contact  with  the  solution. 

When  the  absorption  is  complete,  the  flask  (B)  is  again 
lowered,  thus  drawing  the  gas  back  again  into  A.  One  hun- 
dred cubic  centimeters  minus  the  amount  of  gas  remaining 
shows  the  amount  of  carbonic  acid  gas  absorbed  by  the  caustic 
.potash  solution.  Stop-cock  d  is  now  closed,  stop-cock  e  opened, 
and  (B)  again  raised  thus  forcing  the  gas  into  H.  Here  the 
gas  is  treated  as  it  was  in  D,  (B)  is  then  lowered,  the  gas 
forced  back  into  (A)  and  the  amount  read.  The  gas  unab- 
sorbed  by  the  caustic  potash  minus  the  present  remainder 
shows  the  amount  of  oxygen  which  has  been  absorbed  by  the 
pyrogallic  acid,  or  by  the  phosphorus,  as  the  case  may  be. 

Stop-cock  e  is  now  closed,  stop-cock  /  opened,  and  (B)  again 
raised.  The  gas  is  now  forced  into  F.  Here  especial  care 
must  be  taken  to  be  sure  that  complete  absorption  takes  place. 
When  the  absorption  is  finished,  (B)  is  again  lowered  and  the 
gas  drawn  back  into  (A).  The  previous  remainder  minus  the 
present  remainder  shows  the  amount  of  carbon  monoxide 
which  has  been  absorbed  by  the  cuprous  chloride  solution. 
The  last  remainder  is  usually  reckoned  as  nitrogen,  though  it 
contains  also  small  quantities  of  other  gases.  In  case  there  is 
reason  to  suspect  the  presence  of  considerable  quantities  of 
hydrogen,  a  four-pipette  apparatus,  Fig.  28,  is  used. 

The  gas  left  over  from  the  last  operation  is  increased  by  the 
admission  of  air  from  the  outside  until  it  is  again  as  nearly 
as  possible  100  cubic  centimeters.  The  air  added  will  allow 
of  the  burning  of  a  quantity  of  hydrogen  corresponding  to 
two-fifths  of  its  volume;  that  is,  twice  the  volume  of  the  oxy- 
gen contained  in  the  air.  This  suffices  for  ordinary  producers' 
gas;  but  when  analyzing  "Water  Gas"  or  similar  mixtures 
containing  a  rather  considerable  quantity  of  hydrogen,  a 
smaller  quantity  of  gas  must  be  employed  for  analysis,  or  also 
oxygen  is  used  instead  of  air.  After  reading  off  the  total 
volume,  the  spirit  lamp  (h)  is  lighted  and  turned  so  that  it 


124 


heats  the  capillary  (i)  very  gently.    Then  (B)  is  raised,  g  be- 
ing open  and  all  other  stop-cocks  closed. 


FIG.  28. 

The  gas  passes  through  the  capillary  i,  into  the  pipette  G, 
and  then  on  lowering  (B)  the  gas  passes  back  again  into  the 
burette  (A).  One  end  of  the  palladium  asbestos  should  be- 
come hot  in  this  operation.  The  volume  of  gas  is  read  off 
and  the  passage  through  i  is  repeated.  If,  which  is  usually  not 
the  case,  a  further  contraction  is  now  observed,  the  passage 
through  I  must  be  repeated  once  more.  The  residual  gas  is 
now  finally  measured,  and  two-thirds  of  the  diminution  is 
read  as  hydrogen,  the  other  one-third  being,  of  course,  oxygen. 


125 

REAGENT. 

SOLUTIONS  FOR  ABSORPTION  PIPETTES. 
(Method  in  use  December  7,  1914.) 

Potassium  Hydrate. — Five  hundred  grams  of  potassium  hy- 
drate (not  purified  by  alcohol)  are  dissolved  in  1,000  cubic 
centimeters  of  water.  Capacity:  I  cubic  centimeter  absorbs 
40  cubic  centimeters  of  CO2.  Sodium  hydrate,  at  present,  has 
replaced  KOH,  in  many  works.  This  reagent,  although  not 
quite  as  active,  may  be  used ;  but  solutions  should  be  changed 
oftener  to  avoid  clogging  of  capularies  by  sodium  bicarbonate 
formed. 

Potassium  Pyrogallate. — Fifty  grams  of  pyrogallic  acid  are 
dissolved  in  1,000  cubic  centimeters  of  the  solution  as  made 
above. 

Cuprous  Chloride. — Mix  35  grams  cuprous  chloride  (CuCl) 
and  200  cubic  centimeters  HC1  (specific  gravity  1.19)  and  to 
this  arrange  a  bunch  of  copper  wire  to  reach  the  entire  length 
of  the  bottle. 

LIFE  OF  REAGENTS. 

If  the  solutions  are  protected  from  the  air,  their  life  is  about 
as  follows :  One  cubic  centimeter  of  caustic  potash  solution 
will  absorb  40  cubic  centimeters  or  more  of  CO2.  The  absorp- 
tion of  O  by  pyrogallic  solution  should  be  at  temperatures 
not  less  than  15°  C. ;  I  cubic  centimeter  of  pyrogallol  solution 
will  absorb  about  13  cubic  centimeters  of  O.  Phosphorus  will 
last  a  long  time,  inasmuch  as  the  oxidation  products  are  dis- 
solved off  by  the  water  leaving  the  phosphorus  free  to  com- 
bine with  more  O.  One  cubic  centimeter  of  the  cuprous 
chloride  solution  is  equal  to  about  16  cubic  centimeters  of  CO. 
The  palladium  renews  itself  constantly  by  contact  with  the  air,, 
so  that  its  activity  is  almost  inexhaustible. 

There  is  also  largely  used,  the  modification  of  the  Orsat  ap- 
paratus known  as  Franklyn  Flue  Gas  Analyzer  for  the  deter- 
9 


126 


mination  of  CO2,  O  and  CO,  which  is  explained  by  the  follow- 
ing illustrations.     Its  chief  advantages  are,  its  compactness, 


FIG.  29. 


that  is,  its  parts  are  more  compact  and  not  as  easily  broken  as 
those  of  the  Orsat  Muencke  apparatus. 

CONSTRUCTION  AND  OPERATION  OF  HYGROMETER  FOR  DETER- 
MINING THE  MINIMUM  TEMPERATURE  OF  SATURA- 
TION OF  GAS  IN  DISTRIBUTION  MAINS. 

The  instrument  is  employed  to  determine  the  minimum  tem- 
perature to  which  illuminating  gas  has  been  cooled  on  its 
way  to  the  burner,  its  action  being  dependent  upon  the  fact 


127 

that  the  gas  will  be  saturated  with  vapor  at  the  minimum  tem- 
perature to  which  it  has  been  cooled.  The  instrument  reduces 
a  small  quantity  of  the  gas  back  to  the  minimum  temperature, 
and  upon  further  slightly  cooling,  it  gives  evidence,  in  the 
deposition  of  dew,  that  the  point  has  been  reached.  The  tem- 
perature is  then  noted  on  a  delicate  thermometer  placed  inside 
the  instrument. 

The  function  of  the  instrument  is  therefore  to  duplicate,  on 
a  small  scale,  what  has  previously  taken  place  in  the  main. 

Construction  of  the  Apparatus. 

The  apparatus  consists  of  an  interior  glass  vessel  A  (Fig. 
30)  known  as  the  condensing  tube,  the  glass  jacket  D  sur- 
rounding the  condensing  tube,  the  thermometer  support  O, 
and  the  thermometer  T  which  is  suspended  in  the  condensing 
tube.  The  cap  K  covers  the  top  of  the  instrument  and  carries 
the  burner-head  E.  The  whole  is  mounted  on  a  base  provided 
with  a  cock,  which  is  so  constructed  that  the  gas  may  be  made 
to  pass  straightway  into  the  instrument  or  first  through  either 
one  of  the  scrubbers  (  G  —  //).  The  needle  valve  Z,  is  pro- 
vided in  order  to  permit  of  the  gas  being  passed  directly  to 
the  burner  instead  of  through  the  vaporizing  tube.  The  in- 
strument may  be  taken  apart  at  C  for  the  purpose  of  cleaning 
the  jacket;  the  cap  also  unscrews,  giving  access  to  the  con- 
densing tube.  The  two  scrubbers  may  be  unscrewed  at  the 
bottom  for  filling  and  cleaning. 

Setting  up  the  Apparatus. 

The  support  for  the  apparatus  M  is  screwed  on  to  a  con- 
venient gas  bracket  (no  rubber  connections  should  be  used), 
the  outside  jacket  D  is  screwed  on  the  base  of  the  apparatus  at 
N,  and  the  instrument  then  placed  upright  on  the  support  with 
the  handle  of  the  cock  toward  the  observer.  The  cap  K  is  re- 
moved and  the  thermometer  support  C  pulled  out  and  the 
thermometer  placed  in  position,  as  shown.  The  cap  K  is  then 
replaced  and  surmounted  by  burner-head  £.  The  right-hand 
scrubber  cover  H  should  then  be  unscrewed  from  the  base, 


128 


FIG.  30.— Hygrometer. 


129 

uncovering  the  calcium  chloride  scrubber.  This  tube  should 
be  filled  with  small  pieces  of  calcium  chloride.  Replace  the 
scrubber  cover,  screwing  firmly  into  place  with  the  fingers. 
Likewise  unscrew  the  left-hand  scrubber  cover  C  and  see  that 
the  glass  tube  is  filled  with  rubber  bands;  then  replace  cover. 
The  gas  should  now  be  turned  on  and  lighted,  the  cock  at 
the  base  of  the  instrument  being  turned  so  that  the  gas  passes 
straight  into  the  jacket.  By  turning  the  cock  to  the  right  or 
the  left,  the  gas  can  be  made  to  pass  through  the  scrubbers 
(G  —  H)  at  will,  or  cut  off  entirely.  A  good  flow  of  gas 
(from  2  to  3  feet  per  hour)  should  be  obtained  either  straight- 
way or  through  the  scrubbers.  The  instrument  is  now  ready 
for  observation. 

Making  the  Test. 

Shut  off  the  gas  at  the  cock  on  the  base  of  the  instrument 
and  lift  off  the  burner-head.  Place  the  stem  of  the  small 
funnel  sent  with  the  instrument  through  the  cap  and  pour 
pentane  or  ether  into  the  condensing  tube  until  it  contains 
about  i  inch  of  the  liquid.  Replace  the  burner-head  and  open 
needle  valve  L.  The  gas  is  now  turned  on  with  the  cock  set  so 
that  it  passes  straight  into  the  jacket  and  out  through  the 
burner-head,  the  condensing  tube  being  by-passed.  By 
throttling  the  needle- valve  L,  a  portion  or  all  of  the  gas  may 
be  made  to  bubble  through  the  pentane,  the  rate  of  its  pas- 
sage through  the  pentane  being  regulated  entirely  by  the 
needle-valve.  The  vaporization  of  the  pentane  causes  a  re- 
duction in  temperature  of  the  tube  and  finally  dew  will  be  de- 
posited on  its  outer  surface. 

The  temperature  at  which  the  dew  commences  to  deposit 
opposite  the  bulb  of  the  thermometer  is  noted  and  recorded  as 
the  "dew  point"  or  minimum  temperature  of  the  gas.  When 
this  point  is  reached  the  needle-valve  should  be  opened,  by- 
passing the  condenser  tube.  Soon  the  thermometer  will  rise 
and  the  dew  will  disappear.  The  observance  of  the  point  of 
disappearance  furnishes  a  check  upon  the  first  reading.  The 
gas  before  passing  into  the  instrument  may  be  first  passed 


130 

through  the  scrubbers  (G  —  H)  to  remove  a  portion  of  the 
unfixed  hydrocarbon  vapors  or  water  vapor.  The  functions 
of  these  scrubbers  are  described  in  a  paper  by  C.  C.  Tutwiler, 
published  in  the  Journal  of  the  American  Chemical  Society, 
April,  1908,  and  republished  in  the  American  Gas  Light  Jour- 
nal, of  April  20,  1908. 

TAR. 

For  tar  shipments  it  is,  as  a  rule,  sufficient  to  determine  the 
specific  gravity  and  the  water  in  the  tar.  The  following  two 
methods  are  recommended  for  these  determinations.  For  a 
more  complete  analysis,  refer  to  chapter  on  Tar  Products. 

SAMPLING. 

Tar  is  best  sampled  while  being  unloaded  from  or  loaded  in 
the  tank  car  or  barge.  A  pet  cock  with  a  nipple  projecting 
about  one-third  of  the  diameter,  should  be  placed  in  the  pipe 
line  and  a  continuous  stream  of  tar  drawn  off  into  a  barrel 
during  the  time  of  unloading.  The  pet  cock  should  be  so  regu- 
lated that  the  sample  will  represent  approximately  o.i  per 
cent,  of  the  shipment.  The  tar  may  then  be  stirred  up  and  a 
sample  taken  from  the  barrel.  Samples  of  tar  should  be  placed 
in  heavy  clear  bottles  or  screw  top  tin  cans.  When  necessary 
to  sample  from  storage  tanks,  or  wells,  it  should  be  done  by 
means  of  a  "thief."  This  is  particularly  necessary  when  differ- 
ent shipments  of  tar  of  widely  different  gravities  have  been  run 
into  the  same  tank.  A  simple  and  efficient  apparatus  may  be 
made  from  a  piece  of  2-inch  pipe  provided  with  a  lever  handle 
cock.  This  may  be  closed  by  means  of  a  small  iron  rod  as 
shown  in  Fig.  31. 

By  cutting  away  part  of  the  cock  and  one-half  of  the  plug, 
an  opening  nearly  as  large  as  the  interior  of  the  pipe  is  pro- 
duced. In  taking  the  sample,  the  cock  is  opened  and  the 
"thief"  slowly  lowered  to  the  bottom  of  the  tank,  well,  or  car, 
the  "thief"  having  previously  been  rinsed  with  the  liquid  to 
be  sampled,  the  cock  is  closed,  the  "thief"  is  withdrawn,  and 
the  sample  run  into  a  bottle.  This  operation  is  repeated  until 


a  sample  of  about  I  gallon  is  obtained,  after  which  the  con- 
tents should  be  thoroughly  mixed,  and  a  portion  taken  to  serve 
as  a  smaller  sample  for  analysis. 

It  should  be  noted  that  this  method  cannot  be  used  with 
horizontal  cylindrical  tanks. 


u 

FIG.  31.  -Thief  sampling  tube. 

In  the  case  of  tar  where  there  is  always  a  certain  amount 
of  water  or  ammoniacal  liquor  floating  on  the  surface,  it  seems 
best  to  attempt  to  locate  the  level  of  the  water  or  liquor, 
taking  a  sample  at  this  point,  and  then  sample  a  lower  portion 
of  the  tar  which  is  reasonably  free  from  water,  and  by  calcula- 
tion, estimate  the  total  quantity  of  water  present. 

DETERMINATION  OF  SPECIFIC  GRAVITY. 

When  there  is  no  free  water  the  gravity  may  be  determined 
with  a  hydrometer  after  bringing  the  sample  to  normal  tem- 
perature or  by  observing  the  temperature  and  correcting  as 
follows : 

Specific  gravity  at  70°  C.  =  specific  gravity  observed  at 
jo  c.  +  (T—  t)  X  0.0008. 

It  is  recommended  that  the  specific  gravity  be  taken  at  25° 
C.  Where  more  accurate  results  are  required  the  pycnometer 
bottle  is  recommended.  These  are  straight  sided  thin  glass 
bottles  with  a  ground  stopper  the  full  size  of  the  bottle  and 
provided  with  a  capillary  hole  in  the  center  of  the  stopper. 
The  bottle  is  dried  and  weighed  empty  and  filled  with  water 
at  normal  temperature.  It  is  nearly  filled  with  tar  and  weighed 
again,  it  is  then  completely  filled  with  water,  and  brought  to 


132 


the  normal  temperature,  the  excess  water  removed  and  the 
bottle  dried  and  weighed. 

Specific  eravity  -  (Wt.  bottle  X  tar)  -  (Wt.  bottle) 
~  Wt.  water  full  —  Wt.  water  added" 
DETERMINATION  OF  WATER. 

The  sample  should  be  very  thoroughly  agitated  to  insure 
that  the  portion  taken  for  analysis  is  representative. 


FIG.  32. 


133 

The  apparatus  is  set  up  as  shown  in  Fig.  31. 

Put  25  or  30  cubic  centimeters  of  benzol  in  a  250  cubic 
centimeter  cylinder,  add  200  cubic  centimeters  of  the  well 
mixed  sample,  pour  into  the  copper  still  and  wash  out  three 
times  with  benzol  using  25  to  30  cubic  centimeters  adding 
washings  to  still. 

Fasten  on  Ud  with  the  clamp  using  a  gasket  of  manila  "de- 
tail" paper,  connect  apparatus  as  shown  in  Fig.  27.  Start 
ring  burner  at  top  of  still  and  lower  after  the  water  has  been 
driven  off  until  the  thermometer  reaches  200°  C. 

The  distillate  is  collected  in  two  100  cubic  centimeter  grad- 
uated cylinders. 

Where  an  excessive  amount  of  water  is  suspected  the  dis- 
tilling head  is  replaced  with  the  expansion  chamber  shown  in 
Fig.  32,  the  side  outlet  and  receiver  is  connected  with  a  filter 
pump  and  the  distillation  carried  out  in  a  partial  vacuum. 
The  contents  of  the  receiver  is  then  transferred  to  a  measuring 
cylinder. 

AMMONIA. 

Ammoniacal  Liqiior. 

SAMPLING. 

When  the  liquor  is  contained  in  a  tank  with  straight  sides, 
sampling  is  done  with  a  "thief,"  which  may  be  a  bottle  thief 
or  a  pipe  thief,  A  very  satisfactory  bottle  thief  for  ammonia- 
cal  liquor  may  be  made  as  follows  from  a  one-quart  milk 
bottle. 

Enough  shot  are  put  into  the  bottle  to  overcome  its  buoy- 
ancy and  cause  it  to  sink  easily  when  immersed  in  water.  The 
shot  are  held  in  place  by  pouring  over  them  a  thin  paste  of 
Plaster  of  Paris.  The  bottle  is  provided  with  a  two-hole  cork 
or  rubber  stopper  through  which  pass  two  glass  tubes  pro- 
jecting about  one  inch  above  the  stopper.  One  tube  extends 
just  below  the  stopper;  the  other  to  about  %  inch  above  the 
bottom.  In  use  the  thief  is  lowered  at  even  speed  through 


134 

the  liquor  to  be  sampled  till  it  strikes  bottom,  and  then  immedi- 
ately raised  at  even  speed.  The  speed  must  be  such  that  the 
bottle  is  not  completely  filled  when  it  is  drawn  out  from  the 
liquor.  The  thief  is  emptied,  and  the  operation  repeated  till  a 
sufficient  quantity  for  the  sample  is  obtained.  It  will  be  noticed 
that  the  thief  does  not  take  a  portion  from  the  liquor  lying  be- 
low about  8  inches  from  the  bottom.  When  there  seems  reason 
for  thinking  that  this  bottom  layer  may  be  considerably  differ- 
ent from  the  rest,  the  pipe  thief  should  be  used. 

The  pipe  thief  consists  of  an  iron  pipe  of  1^4  inches  to  2 
inches  size,  as  desired,  long  enough  to  reach  to  the  bottom 
of  the  tank.  Its  lower  end  is  provided  with  a  plug-cock  hav- 
ing a  lever  handle  which  points  across  the  pipe  when  the  cock 
is  open.  A  rod  or  chain  is  attached  to  the  end  of  the  handle. 
The  thief  is  slowly  lowered,  with  the  cock  open  to  the  bottom 
of  the  tank.  The  cock  is  then  closed  by  pulling  on  the  rod 
or  chain,  and  the  thief  withdrawn  and  emptied.  The  operation 
is  repeated  till  a  sufficient  sample  is  collected. 

When  liquor  can  be  sampled  during  pumping,  this  should 
be  done  in  preference  to  taking  a  sample  from  the  tank.  This 
is  especially  true  with  tank  cars  or  other  horizontal  cylindri- 
cal tanks.  A  pet  cock  should  be  attached  to  the  pipe  line  on 
the  outlet  of  the  pump  by  a  nipple  projecting  into  the  line 
about  one-third  of  the  diameter  of  the  latter.  A  small  stream 
of  liquor  should  be  drawn  at  steady  speed  from  the  pet  cock 
through  a  tube  into  a  covered  receiver  of  not  much  larger 
size  than  the  sample  desired.  Where  the  question  of  sale  is 
involved,  an  amount  equal  to  o.i  per  cent,  of  the  total  quan- 
tity should  be  collected  in  the  receiver.  After  shaking,  a 
sample  is  taken  from  the  latter  for  the  laboratory. 

In  collecting  a  running  sample,  as  described  above,  it  is 
necessary  that  the  rate  of  flow  and  the  pressure  in  the  line 
where  the  pet  cock  is  inserted  be  uniform  throughout  the  un- 
loading of  the  tank.  When  a  tank  is  unloaded  by  gravity, 
these  conditions  are  not  fulfilled  and  therefore  a  pet  cock  in 
the  line  does  not  give  the  true  average  sample.  In  such  a 
case,  however,  an  approximately  correct  sample  can  be  ob- 


135 

tained  if  several  running  samples  are  taken,  each  represen- 
tative of  a  definite  fraction  of  the  whole  quantity,  such  as  one- 
sixth  or  one-eighth.  Equal  portions  are  taken  from  each  sep- 
arate sample,  and  mixed  to  form  the  composite  sample. 

In  sampling  from  a  horizontal  cylindrical  tank,  the  thief 
cannot  be  used,  because  equal  depths  of  liquor  at  different 
elevations  represent  quite  different  volumes.  A  good  approxi- 
mation to  a  true  average,  however,  can  be  made  by  taking 
several  samples  at  varying  depths,  which  latter  are  chosen  to 
represent  a  division  of  the  tank  into  equal  parts  by  volume. 
Equal  amounts  are  taken  from  the  various  samples,  and  mixed. 
The  greater  number  of  the  samples,  the  more  representative 
is  the  mixture.  The  following  table  shows  the  depths,  ex- 
pressed in  per  cent,  of  the  diameter  at  which  samples  should 
be  taken,  when  six,  eight,  ten  and  twelve  samples  are  desired : 

For  6  samples    For  8  samples    For  10  samples  For  12  sample 

Percentage            13.7                 11.3                   9.8  8.6 

30.0                 24.4                 20.7  18.3 

of                    43-6                35-3                 3°-o  26.2 

56.4                 45-2                 38.3  33-3 

diameter             70.0                 54.8                  46.1  40.1 

86.3                 64.7                  53.9  46.7 

75-6                  61.7  53.3 

88.7                 70.0  59-9 

79.3  66.7 

90.2  73-8 

81.7 

91.4 

These  depths  represent  the  centers  of  gravity  of  zones  of 
equal  volume. 

For  collecting  these  samples,  the  bottle  thief  is  suitable. 
The  ends  of  a  short  piece  of  rubber  tubing  with  a  string  tied 
around  its  middle  are  pushed  lightly  over  the  tubes  of  the 
thief,  thus  sealing  them.  The  bottle  is  then  lowered  gently 
to  avoid  disturbance  of  the  strata,  till  the  tops  of  the  tubes 
are  at  the  right  depth  for  taking  the  first  or  top  sample.  The 
rubber  tube  is  then  drawn  off  and  the  thief  allowed  to  fill. 
The  second  sample  from  the  top  is  then  taken,  etc. 


i36 

The  foregoing  table  is  intended  for  use  on  completely  filled 
tanks.  It  may,  however,  be  used  for  sampling  partially  filled 
tanks,  without  much  error,  if  several  samples  are  taken,  and 
special  calculation  is  made  as  follows  for  the  top  sample :  The 
boundary  between  zones  is  assumed  for  this  purpose  to  be 
half-way  between  the  centers  of  adjoining  zones.  The  top 
zone  will  then  consist  of  the  liquor  from  the  surface  to  the 
first  zone  boundary  below,  and  the  top  sample  should  be  taken 
half-way  between  these  points.  The  amount  of  this  top  zone 
sample  taken  for  the  mixed  sample,  should  be  in  the  ratio  of 
the  actual  depth  of  the  top  zone  to  its  full  depth  according 
to  the  table. 

Tanks  and  tank  cars  of  ammoniacal  liquor,  often  contain 
tar,  which  may  either  float  or  sink  depending  on  its  nature. 
To  estimate  the  depth  of  the  floating  tar,  use  a  glass  tube  of 
*/%  inch  or  more  diameter  whose  lower  end  is  fitted  with  a 
rubber  stopper,  which  may  be  drawn  up  into  the  tube  by  a 
string  fastened  into  the  stopper  and  passed  up  through  the 
tube.  Lower  the  tube  slowly  through  the  tar  layer,  with  the 
stopper  suspended  well  below  the  tube  end.  When  the  tube 
end  is  well  into  the  liquor,  draw  up  the  stopper,  closing  the 
tube.  Measure  the  depth  of  the  tar  layer. 

To  measure  the  depth  of  tar  in  the  bottom  of  the  tank, 
attach  a  piece  of  cotton  wicking  to  a  rod.  Wet  the  wicking 
with  benzol  or  other  light  colored  tar  solvent,  and  put  the  rod 
into  the  tank.  The  tar  will  color  the  moist  wicking. 

SPECIFIC  GRAVITY. 

The  determination  of  specific  gravity  is  made  by  hydrom- 
eter. A  regular  specific  gravity  hydrometer,  graduated  to  read 
to  the  third  decimal  place  is  used.  However,  in  cases  of  doubt 
or  dispute,  a  pycnometer  (Sprengel  tube)  should  be  used. 

The  standard  temperature  for  taking  the  gravity  is  60° 
F.  The  gravity  is  referred  to  water  at  60°  F.  A  hydrometer 
jar  of  the  liquor  to  be  tested  should  be  brought  to  that  tem- 
perature by  immersion  in  water,  and  the  reading  taken. 


137 

When  it  is  desired  to  know  accurately  the  weight  of  liquor 
present  in  a  tank  or  tank  car,  the  gravity  must  naturally  be 
taken  at  the  temperature  at  which  the  volume  of  the  liquor  is 
also  measured.  This  may  be  done  by  taking  the  gravity  of  a 
freshly  drawn  sample  at  the  tank;  or  the  temperature  may  be 
noted  and  the  regular  sample  brought  to  that  temperature  in 
the  laboratory  for  a  determination  of  the  gravity. 

The  Committee  recommends  the  general  use  of  the  specific 
gravity  scale  in  reporting  the  gravity  of  ammoniacal  liquor. 
It  recognized,  however,  that  the  use  of  the  Twaddle  hydrom- 
eter is  common  in  several  of  the  older  companies.  Readings 
in  the  Twaddle  scale  may  be  changed  into  readings  on  the 
specific  gravity  scale  by  the  use  of  the  following  formula : 

Specific  gravity  =  i.o  divided  by  0.005  Tw. 

The  objection  to  the  use  of  the  Twaddle  scale,  is  that  it  is 
often  assumed  that  the  value  of  the  liquor  in  terms  of  "ounce 
strength"  may  be  found  by  multiplying  the  Twaddle  reading 
by  two.  There  is,  however,  no  general  numerical  connection 
between  the  hydrometer  reading  of  a  liquor  and  its  content  of 
ammonia. 

(In  any  one  plant,  operating  regularly  under  the  same  con- 
ditions and  using  the  same  coal,  it  is  true  that  an  increase  in 
the  strength  of  the  liquor  will  generally  be  accompanied  by  an 
increase  in  its  gravity,  and  in  such  case  the  hydrometer  read- 
ing offers  a  simple  means  of  following  the  daily  operation  of 
condensers,  scrubbers,  etc.) 

Since  considerable  changes  in  the  reading  occur  when  the 
temperature  is  much  different  from  60°,  and  since  it  is  incon- 
venient to  adjust  the  temperature  of  the  liquor  in  works  test- 
ing, the  following  table  has  been  prepared  to  find  the  equiv- 
alent reading  at  60°  from  a  reading  taken  at  a  different  tem- 
perature. The  numbers  are  degrees  on  the  Twaddle  hydrom- 
eter. The  table  is  not  perfectly  correct  for  all  ammoniacal 
liquors  but  is  sufficiently  so  for  the  routine  testing  for  which 
it  is  intended. 


138 


w 

rt 

88888888§ 

0 

S^ffS,^^!?^ 

BU 

p 

j^ 

oo  r^\o  10  T  co  PI  M 

r^vo  10  -<t  co  w  M        i 

s»,  a 

<! 
- 

£ 

PI 

OS 

oo  Tt~w  r-*co^ioo  10 

0    M    (N    (N    COcOrMOrr 

1  K  S, 

w 

oo'  t^-vd  10  TT  co  pi  M 

t^.vO    IO  ^"  f*>  04    IH             I 

!|| 

- 
w 

00 

g^s-crs^s5?? 

00 

J?^^C0^5^-K^ 

fl  fi  "S 

H  ^§ 

H 

OO  l^^O   IO  •<*•  CO  PI    M 

•  a  ft 

W 
,4 

g 
p 

55 

smm^ 

" 

OO   COO  lO^vO   M   IO^\ 
M   w   rCcO^Ti-ioiOcO 
t^.\O  IO  ^f  CO  W   M          I* 

I!} 

<! 

as 

OO  vO   ^  CO  W   M   ONt^lO 

cooo^OMOO^oor. 

n    fe  * 

~  1  8" 

H 

s 

10 

oo"  r^-so  10  -<i-  co  oi  M 

^ 

t^-^O*  IO  4  CO  Pi  i-I          |' 

a  »  10 

0-0 

(4 
p< 

IO 

O*   O  OO  VO   iOrO>-<   5s  *""" 

10 

OOCOOOCO^CO^M^ 

?-  ? 

g 

06  l"**vC   IO  ^  ro  CS  M 

t^^O   iO  ^  to  W   t-<          | 

*li 

Q 
g 

•<*• 

t^COPIOSOOvOCOM^ 

^; 

cooo  Pir.  covo  O^M 

-  §  <1 
§1  d 

CM 

oo  r^\o  10  ^"  co  PI  *H 

t^<O    IO  Tf  CO  PI    IH              1 

:Ji 

O 

a 

K 

COPIPIPIPIW'HWM 

rs 

oo  co  r^  M  vo  o  TI-  t^oo 

CO  •»)-  •<*•  10  IO>O  >O  >O   PI 

^|8 

«    S  o 

,4 

oo  r>«vo  10  4  co  pi  M 

t^-vO  IO  T  CO  PI  w          1 

g   «  t> 

W   ^3    <U 

t4 

«< 

u 

PI 

10  w  avvo  co  o  r^  10  «- 

COCOPIPIPIPII-II-II-I 

PI 

cO^jOg^O.0 

||| 

«! 

OO^^^COPIM 

r>>vo  10  ^  co  w  M       j 

fcl    ^ 

fc 
O 

i 

M 

33R<ras>g«eg> 

M 

.oPi^as^oco^ 

*  8« 

in 

00    t^VO    IO  TT  CO  PI    IH 

t^vO  >O  •*  CO  PI   w 

S  .  B 

(U      J3         <H 

to 

o 

& 

^S'ftaffsa&J 

o. 

B'ftStftfR.SrRS 

*  -  £   . 

*-•    O  «-;  o 

o  ^  S  ^ 

>< 

OO^VO^^-COWM 

C-vO^^tOPl'-     '    |' 

_.    <u    a>    J- 

s  ^  *-  ^s 

S 

^ 

0 

t^ 

$ 

J.O^MCO^^ 

!"§  s^ 
1,8  S3 

A 

oo  i^\o  10  ^  to  PI  IH 

t^.vO   IO  ^  CO  PI  IH          1 

0    •"     <U    T3 

CSS  g 

a 
g 

* 

oo'  ri-o  10  4  co  PI  « 

8 

r^vo'  in  •*  to  «  IH        i" 

3    tn    (fi    ^ 

2^  ?1 

X  -°  ^  Si 

§ 

fc 

C/2 

5? 

oo'  t^-^o'  10  TJ-  CO  PI  i-i 

£ 

l^  ON  PI   ^-00   ON  PI   •*•  T}- 

t^.\O   IO  4  CO  pi  M          I* 
| 

P  1  Q-  i 

^§{58 

FH 

§ 

* 

oo'  r^-o'  10  T}-  co  N  w 

$ 

PI   CO\O  CX)   M   PI  IO\O   P» 

t-.  i-.  r>-  t^-oo  oo  oo  oo  w 
r^-vo*  10  4  co  PI  M 

!-"  ts  "S  j 

5  5  2  - 
.sS  4« 

(A 

10 

\O    lOlO-'TTj-COPI    P?C" 

% 

t^oo  o  PI  ^"  10  r^oo  o 
r^  t^oo  oo  oo  oo  oo  oo  M 

1  §-s  ^ 

e  be  cs  -o 

O 

oo  i^^o  10  •*  co  PI  »H 

t^vO  IO  Tj-  CO  PI  IH          1 

•§|  S  j; 

M 

5 

00  t^-vd  IO  •*  CO  PI  IH 

3 

r^vo"  10  -<i-  co  pi  w 

lisa 

Zl    *~   v    <u 

£  h  1  i 

M 

o 
o 

5 

M  Tj-oO  COOO   O   cOsO  00^ 

r>.vq  10  10  TI-  •*  co  PI  IH 
oo'  r^-^d  10  4  to  p5  w 

CO 

(^•-0'  10  -4  co  PI  M    '   i' 

Jfli 

^2  a  >,  cs 

CS       O     rC 

w 

M 

£3 
JH 

a 

^i-OO  M  vo  O  co  *O  t^  ^\ 

r^\o  ^o  10  10  ^  co  PI  M 
oo  r>-AC  10  4  co  PI  IH 

PI 

r^^o*  10  4  co  PI  H!    '   i* 

Sfc*i 

5   fl    ^     3 

•< 
j* 

„ 

00   w   10  ON  PI   IO  r^OO   O\ 

t~*  t^VO    IO  IO  ^-  CO  PI    IH 

_, 

vONOvO-O^Og-^PI 

2  *   ft  w 

3  1;  a  °0 

W 
PL, 

oo  r^vo  10  'i-  co  N  IH 

r^^o  10  ^  co  w  »-»        i 

H  S  I* 

0 

oo  {CS^S  ^^%r?8 

888888888 

II 

H 

00     t^^O     IO  ^"  CO  C1)     M 

-; 

00   t>-vO   IO  "^  CO  CS   M     I 

££.2 

139 

Ammoniacal  Liquor. 

DETERMINATION  OF  TOTAL  AMMONIA. 
APPARATUS  REQUIRED. 

A  500  cubic  centimeter  round-bottomed  long-necked  flask  (a 
Kjeldahl  flask)  into  whose  neck  is  set  by  a  rubber  stopper  a 
bulb  tube  with  the  bulb  portion  bent  to  45°  off  the  vertical,  or 
some  other  form  of  Kjeldahl  connecting  bulb,  to  prevent  the 
mechanical  carrying  of  spray  into  the  condenser. 

Inside  an  ordinary  glass  Liebig  condenser  jacket  is  slipped 
a  block  tin  tube  about  ^  inch  outside  diameter,  in  place  of  the 
usual  glass  condenser  tube.  The  tin  tube  can  be  obtained 
from  a  plumbing  house.  There  is,  however,  no  objection  to 
the  use  of  a  glass  condenser  as  shown  in  Fig.  28  if  preferred 
by  the  chemist.  About  7  inches  of  tin  tube  projects  beyond 
the  jacket  and  this  portion  is  bent  back  on  itself  to  an  angle 
of  135°  from  the  vertical  and  joined  by  rubber  tubing  to  the 
connecting  bulb  previously  mentioned. 

To  the  lower  end  of  the  tin  condenser  tube  is  attached  a 
plain  bulb  tube  of  about  150  cubic  centimeters  capacity.  The 
lower  end  of  this  will  dip  into  the  beaker  of,  standard  acid. 
The  object  of  the  bulb  is  to  prevent  the  accidental  sucking  back 
of  the  contents  of  the  beaker.  The  equipment  of  flask  and 
condenser  should  be  carried  on  a  single  stand. 

There  will  also  be  needed  one  25  cubic  centimeter  pipette 
for  sampling  weak  liquors ;  and  one  100  cubic  centimeter  pip- 
ette and  one  1,000  cubic  centimeter  graduated  flask  for  use 
with  concentrated  liquors.  On  account  of  the  inaccuracy  of 
some  of  the  volumetric  apparatus  on  sale,  the  pipettes  should 
be  checked  by  filling  them  with  boiled  distilled  water  at  room 
temperature,  discharging  into  tared  small  stoppered  bottles 
and  weighing  the  water.  The  weight  should  not  vary  by  more 
than  2  parts  in  1,000  from  the  weight  given  in  the  tables  (See 
circular  No.  19  of  the  Bureau  of  Standards  for  complete 
tables).  The  water  from  a  25  cubic  centimeter  pipette  cali- 
brated for  20°  C.,  should  weigh  24.948  grams  at  15°  C. ;  24.929 
grams  at  20°  C.;  24.904  grams  at  25°  C.  Water  discharged 


140 


FIG.  33. 


from  a  100  cubic  centimeter  pipette,  calibrated  for  20°  C. 
should  weigh  99.793  grams  at  15°  C. ;  99718  grams  at  20°  C.; 
99.617  grams  at  25°  C.  New  marks  should  be  made  on  the 
pipettes  if  they  are  in  error  by  more  than  the  allowed  amount. 
It  should  be  determined  also  that  the  1,000  cubic  centimeter 
flask  holds  ten  fillings  from  the  100  cubic  centimeter  pipette. 

Operation  A. — For  liquor  under  3  per  cent,  ammonia  (ordi- 
nary weak  liquor).  Put  150  cubic  centimeters  distilled  water 
into  the  500  cubic  centimeter  flask  and  run  in  25  cubic  centi- 
meters of  liquor  from  the  pipette.  Add  25  cubic  centimeters 
of  30  per  cent,  sodium  hydroxide  solution  (300  grams  NaOH 
in  700  cubic  centimeters  water)  and  a  small  piece  of  gran- 
ulated zinc  to  prevent  bumping.  The  addition  of  a  small  bit 
of  parafnne  will  hinder  troublesome  foaming. 

Put  50  cubic  centimeters  of  normal  sulphuric  acid  and  50 
cubic  centimeters  of  water  in  a  400  cubic  centimeter  beaker 
and  support  the  beaker  so  that  the  bulb  tube  on  the  condenser 
end  dips  about  y2  inch  below  the  surface  of  the  acid.  Con- 
nect up  the  apparatus  and  heat  up  gently  till  the  air  is  expelled 
and  the  boiling  is  steady.  All  the  ammonia  will  be  driven  off 
with  the  first  100  cubic  centimeters  of  distillate.  From  time 
to  time  lower  the  beaker  so  that  the  seal  of  the  bulb  tube  is  not 
much  over  ]/2  inch.  When  about  100  cubic  centimeters  has 
distilled  over,  lower  the  beaker  clear  of  the  tube  and  allow 
the  distillate  to  rinse  the  inside  of  the  latter.  Wash  the  out- 
side with  a  wrash  bottle. 

Titrate  the  solution  in  the  beaker  with  half-normal  am- 
monium hydroxide  or  normal  sodium  hydroxide,  using  coch- 
ineal or  methyl  orange  as  indicator. 

Calculate  the  number  of  cubic  centimeters  of  normal  acid 
which  have  been  neutralized  by  the  ammonia  from  the  liquor. 
The  percentage  of  ammonia  is  found  by  multiplying  this  num- 
ber of  cubic  centimeters  by  the  factor  0.06813  and  dividing  by 
the  specific  gravity  of  the  liquor.  In  calculating  the  percen- 
tage strength,  the  gravity  used  should  properly  be  that  of  the 
liquor  at  temperature  of  pipetting.  The  difference,  however, 
10 


142 

may  be  disregarded  unless  the  temperature  varies  from  60° 
F.  by  more  than  10°  or  12°. 

B.  For  Concentrated  Liquors. — One  hundred  cubic  centi- 
meters of  the  concentrated  liquor  are  made  up  to  1,000  cubic 
centimeters  and  an  aliquot  of  100  cubic  centimeters  taken  for 
the  distillation.    This  is  put  in  the  distilling  flask  with  75  cubic 
centimeters  of  water  and  25  cubic  centimeters  of  30  per  cent, 
caustic  soda  solution.     Zinc  and  paraffine  are  added  as  before. 

The  ammonia  is  received  in  100  cubic  centimeters  of  normal 
sulphuric  acid  in  a  400  cubic  centimeter  beaker,  or  in  125 
cubic  centimeters  for  very  strong  liquor. 

Calculate  the  number  of  cubic  centimeters  of  normal  acid 
neutralized  by  the  ammonia.  For  percentage  of  ammonia  mul- 
tiply this  number  of  cubic  centimeters  by  0.17033  and  divide 
by  the  specific  gravity  of  liquor. 

C.  For  Waste  Liquors  From  Ammonia  Stills. — Two  hun- 
dred cubic  centimeters  of  the  waste  liquors  are  put  in  the  dis- 
tilling flask,  with  25  cubic  centimeters  of  30  per  cent,  caustic 
soda  solution  together  with  zinc  and  paraffine.     One  hundred 
cubic  centimeters  is  distilled  off  and  received  in  20  cubic  centi- 
meters of  normal  acid  diluted  with  80  cubic  centimeters  of 
water. 

Calculate  the  number  of  cubic  centimeters  of  acid  neutral- 
ized by  the  ammonia.  For  percentage  of  ammonia,  multiply 
this  number  of  cubic  centimeters  by  0.00852. 

The  Committee  strongly  recommends  reporting  the  amount 
of  ammonia  in  liquor  as  a  percentage,  as  described  above. 
Several  of  the  older  companies,  however,  are  in  the  habit  of 
reporting  in  so-called  "ounce-strength."  Two  different  mean- 
ings appear  to  be  given  to  this  latter  term.  It  is  sometimes 
defined  to  mean  the  number  of  ounces  of  100  per  cent,  sul- 
phuric acid  which  will  be  neutralized  on  direct  titration  by 
i  Imperial  gallon  (277.27  cubic  inches)  of  this  liquor.  Only 
the  free  ammonia  is  taken  into  account  in  this  test.  For  the 
determination,  see  the  determination  of  free  ammonia  by  titra- 
tion, as  described  below. 

Again  "ounce-strength"  is  defined  to  mean  the  number  of 


143 

ounces  of  100  per  cent,  sulphuric  acid  which  will  be  neutral- 
ized by  the  total  ammonia  contained  in  I  U.  S.  gallon  (231 
cubic  inches).  If  figures  in  "ounce-strength"  of  this  definition 
are  sought  they  may  be  obtained  from  the  results  of  the  dis- 
tillation analysis  above  described  by  the  following  calculation : 

A.  For  Weak  Liquors. — Multiply  the  number  of  cubic  cen- 
timeters of  acid  which  have  been  neutralized  by  the  ammonia 
from  the  liquor,  by  the  factor  0.26196. 

B.  For  Concentrated  Liquors. — Multiply  the  number  of 
cubic  centimeters  by  the  factor  0.6549. 

C.  For  Waste  Liquors. — Multiply  the  number  of  cubic 
centimeters  by  the  factor  0.03275. 

It  should  be  noted  that  the  ounce  strength  as  thus  found  is 
really  the  ounce  strength  of  the  liquor  at  the  temperature  of 
sampling  with  the  pipette.  The  ounce  strength  will  increase 
proportionately  as  the  gravity  increases  with  lower  tempera- 
tures and  vice  versa.  The  difference  in  value  for  10°  F.  will 
amount  to  about  1.5  parts  of  1,000.  The  liquor,  as  sampled, 
should  not  therefore  vary  by  more  than  10°  from  60°  F. 

In  the  method  described  for  the  determination  of  ammonia 
in  ammoniacal  liquor,  it  is  usually  assumed  that  ammonia  is 
the  only  substance  distilling  off,  which  will  neutralize  the  sul- 
phuric acid.  This  is  not  strictly  correct,  for  the  pyridine 
present  in  the  liquor  will  distil  and  will  neutralize  some  of  the 
acid,  thereby  causing  the  apparent  ammonia  found  to  be  larger 
than  the  true  value.  The  amount  of  pyridine  is  usually  small 
but  where  high  accuracy  is  desired,  a  correction  should  be 
made  for  it,  in  the  following  manner: 

In  the  determination  of  pyridine,  as  described  below,  there 
is  found  the  number  of  cubic  centimeters  of  normal  acid 
which  are  neutralized  by  the  pyridine  contained  in  a  given 
amount  of  liquor.  From  this  calculate  the  number  of  cubic 
centimeters  of  acid  corresponding  to  the  pyridine  contained 
in  the  amount  of  liquor  taken  for  the  ammonia  test.  Subtract 
this  from  the  number  of  cubic  centimeters  of  acid  neutralized 
in  the  ammonia  test,  and  the  result  is  the  number  of  cubic 
centimeters  neutralized  by  the  ammonia  alone. 


144 

To  detect  possible  errors  in  the  distillation  test  for  am- 
monia, it  is  well  to  make  a  test  on  a  pure  ammonium  salt. 
For  this  purpose  pure  ammonium  sulphate  or  chloride  should 
be  dissolved  in  hot  water,  filtered  and  recrystallized.  After 
drying  at  50°  C.,  4.5  to  5.0  grams  are  put  in  the  distillation 
flask  with  175  cubic  centimeters  of  water  and  25  cubic  centi- 
meters of  30  per  cent,  caustic  soda.  The  ammonia  is  received 
in  100  cubic  centimeters  of  normal  acid.  If  the  equivalent  of 
sulphate  of  ammonia  found  differs  by  more  than  0.3  of  I  per 
cent,  from  the  100  per  cent,  expected,  the  error  should  be  cor- 
rected. It  will  very  likely  be  found  in  the  standard  solutions 
used. 

Free  Ammonia. 

Free  ammonia  is,  by  definition,  that  which  can  be  distilled 
off  from  liquor  by  boiling  alone,  without  the  use  of  alkali. 
Its  determination  is  made  exactly  as  the  determination  of  total 
ammonia,  described  above,  except  that  no  caustic  soda  solu- 
tion is  used.  The  results  are  calculated  in  the  same  way  and 
by  the  same  factors. 

For  greater  convenience,  when  the  utmost  accuracy  is  not 
desired,  the  determination  of  free  ammonia  may  be  made  by 
direct  titration,  as  described  below. 

For  weak  liquors,  25  cubic  centimeters  of  the  liquor  is 
diluted  with  100  cubic  centimeters  of  water,  and  the  solution 
titrated  with  normal  sulphuric  acid,  using  methyl  orange  as 
indicator.  The  indicator  is  gradually  destroyed  by  something 
in  the  solution.  If  the  amount  of  acid  needed  is  approximately 
known,  it  is  better  to  run  in  almost  that  amount,  without  adding 
indicator,  agitate  the  solution  till  most  of  the  gas  has  gone, 
add  a  few  drops  of  indicator  and  bring  to  the  end  point.  In 
any  case,  if  there  is  delay  in  reaching  the  end  point,  a  couple 
of  drops  of  additional  indicator  must  be  added  from  time  to 
time. 

For  concentrated  liquors  100  cubic  centimeters  are  diluted 
to  1,000  cubic  centimeters,  an  aliquot  of  100  cubic  centimeters 


145 


taken  and  mixed  with  100  cubic  centimeters  of  water.  Titra- 
tion  is  performed  as  for  weak  liquors. 

When  results  are  desired  in  "ounce-strength,"  meaning  the 
ounces  of  sulphuric  acid  neutralized  by  the  free  ammonia  in 
i  Imperial  gallon,  as  previously  denned,  the  calculation  is  per- 
formed thus. 

For  weak  liquors,  multiply  the  number  of  cubic  centimeters 
of  acid  used  by  the  factor  0.31443. 

For  concentrated  liquors,  multiply  the  number  of  cubic  cen- 
timeters of  acid  used  by  the  factor  0.78608. 

The  results  by  direct  titration  check  fairly  well  with  those 
by  distillation,  being  usually  a  trifle  higher.  Where  speed  is 
of  more  importance  than  high  accuracy,  the  direct  titration  is 
preferable. 

Fixed  Ammonia, 

To  the  residue  left  in  the  distillation  flask,  after  boiling  off, 
the  free  ammonia  are  added  100  cubic  centimeters  of  water 
and  25  cubic  centimeters  of  30  per  cent,  sodium  hydroxide 
solution.  The  ammonia  is  distilled  off  and  received  in  20 
cubic  centimeters  of  normal  acid,  diluted  to  100  cubic  centi- 
meters. Calculation  of  results  is  the  same  as  described  under 
"total  ammonia." 

Other  Constituents  of  Liquor. 

A.  Pyridine: — 200  cubic  centimeters  of  weak  liquor,  or  25 
cubic  centimeters  of  concentrated  liquor  diluted  to  200  cubic 
centimeters  are  neutralized  with  sulphuric  acid  of  about  1 :  5 
strength.  The  directions  given  for  the  direct  titration  of  free 
ammonia  should  be  followed  in  reaching  the  neutral  point. 
Pyridine  will  now  be  combined  as  pyridine  sulphate.  Add 
about  10  cubic  centimeters  of  normal  ammonium  hydroxide, 
or  its  equivalent,  put  in  an  ammonia  distillation  flask  and  distil 
off  as  for  total  ammonia,  into  about  25  cubic  centimeters  of 
normal  sulphuric  acid  or  its  equivalent,  diluted  to  100  cubic 
centimeters  with  water.  Collect  about  100  cubic  centimeters 
of  distillate  which  will  contain  all  the  pyridine. 


146 

Put  the  distillate  in  an  ammonia  distillation  flask  with  10 
cubic  centimeters  of  normal  sodium  hydroxide  solution  and 
distil  into  50  cubic  centimeters  of  water  in  a  250  cubic  centi- 
meter beaker.  Collect  100  cubic  centimeters  of  distillate  which 
will  contain  the  pyridine  together  with  considerable  ammonia. 

The  beaker  now  contains  150  cubic  centimeters.  Add  6 
drops  of  phenolphthalein  indicator  solution  (5  grams  per  liter) 
and  run  in  normal  sulphuric  acid  till  the  pink  color  is  just 
discharged.  Read  the  burette  and  run  in  0.13, cubic  centimeter 
more.  (A  test  will  show  that  with  this  volume  of  solution  and 
amount  of  indicator,  the  phenolphthalein  color  will  be  dis- 
charged by  0.13  cubic  centimeter  less  of  normal  acid  than  is 
required  to  completely  neutralize  the  ammonia  when  methyl 
orange  indicator  is  used.)  Noting  the  reading  of  the  burette, 
add  I  drop  of  methyl  orange  and  titrate  to  the  pink  color. 
The  amount  of  acid  used  to  turn  the  methyl  orange  indicates 
the  amount  of  pyridine  present.  One  cubic  centimeter  of  acid 
indicates  0.079  gram  of  pyridine,  equivalent  to  0.017  gram  of 
ammonia. 

Acid  Radicals. 

The  following  methods  are  taken  from  the  1909  and  previous 
Reports  of  the  Chief  Inspector  under  the  Alkali,  etc.,  Works 
Acts.  They  represent  the  result  of  work  covering  several 
years,  carried  on  in  the  laboratories  of  the  Chief  Inspector 
in  England. 

Carbonate: — 10  cubic  centimeters  of  liquor  (more  if  dilute) 
are  diluted  to  400  cubic  centimeters  and  10  cubic  centimeters 
of  2N  ammoniacal  solution  of  calcium  chloride  are  added. 
The  whole  is  then  heated  for  iT/2  to  2  hours  in  a  water  bath  at 
100°  C.,  the  flask  being  closed  by  a  Bunsen  valve.  (That  is 
the  flask  is  closed  by  a  rubber  stopper  carrying  a  short 
glass  tube  over  which  is  slipped  a  piece  of  rubber  tubing 
plugged  at  its  top  end.  Between  the  plug  and  the  glass 
tube,  a  slit  about  J4  mch  long  is  made  in  the  rubber  tube. 
Gases  can  escape  but  air  from  outside  cannot  enter.)  The 
precipitated  calcium  carbonate  is  filtered  off,  washed  by  de- 


147 

cantation,  and  dissolved  in  N/2  hydrochloric  acid.  The  small 
amount  of  calcium  carbonate  left  on  the  filter  paper  is  best 
recovered  by  incineration  and  is  added  to  the  solution.  The 
excess  of  acid  is  titrated  with  N/2  sodium  carbonate. 

Sulphide: — 10  cubic  centimeters  of  liquor  are  diluted  to 
500  cubic  centimeters,  acidified  with  hydrochloric  acid,  and 
titrated  with  N/io  iodine  (starch  indicator).  The  volume  of 
N/io  iodine  required  determines  how  much  liquor  to  take  for 
the  actual  determination  of  sulphide  to  follow.  Ten  cubic 
centimeters  (or  more  if  the  sulphide  is  apparently  small  in 
quantity)  are  run  into  an  excess  of  N/5  ammoniacal  zinc  chlo- 
ride solution,  diluted  to  about  80  cubic  centimeters.  The  solu- 
tion is  warmed  to  coagulate  the  sulphide,  filtered,  and  washed 
with  warm  water  of  40°  to  50°  C.  temperature.  The  zinc 
sulphide  on  the  filter  is  washed  into  excess  of  N/io  iodine, 
acidified  with  hydrochloric  acid  (the  last  traces  being  washed 
through  the  filter  with  cold  dilute  acid).  After  vigorous  shak- 
ing to  complete  the  solution  of  the  sulphide,  the  excess  of 
iodine  is  titrated  with  N/io  thiosulphate. 

Chloride: — 250  cubic  centimeters  of  liquor  are  boiled  to 
expel  sulphide,  cooled,  and  made  up  to  250  cubic  centimeters. 
Dilute  10  cubic  centimeters  of  this  to  150  cubic  centimeters, 
add  25  to  50  cubic  centimeters  of  hydrogen  peroxide  (3  per 
cent,  or  "10  volume"  solution,  free  from  chloride),  boil  for 
15  minutes,  add  6  drops  of  a  10  per  cent,  solution  of  potassium 
chromate,  and  continue  the  boiling  2  minutes.  Should  the 
organic  matter  resist  oxidation,  more  peroxide  must  be  added 
and  the  boiling  continued  with  addition  of  potassium  chromate 
as  before.  Add  a  slight  excess  of  sodium  carbonate,  re-boil 
for  I  minute,  filter,  cool,  make  up  to  250  cubic  centimeters  and 
titrate  an  aliquot  portion  with  N/io  silver  nitrate  (potassium 
chromate  indicator)  after  bringing  to  the  neutral  point  with 
dilute  nitric  acid.  A  blank  experiment  is  made  with  10  cubic 
centimeters  N/io  NaCl  and  the  same  volume  of  water,  per- 
oxide, and  chromate,  to  determine  the  correction  for  traces  of 
chloride  in  the  reagents  used.  (Twenty-five  cubic  centimeters 


148 

of  peroxide  should  not  contain  more  than  the  equivalent  of  0.2 
to  0.3  cubic  centimeters  N/io  HC1. 

Thiocyanate: — i.  Ferrocyanide  absent — 50  cubic  centimeters 
of  the  solution  are  treated  with  lead  carbonate  to  remove  sul- 
phide and  the  lead  sulphide  and  carbonate  filtered  off  and 
washed.  To  the  filtrate,  sodium  bisulphite  containing  a  little 
free  sulphur  dioxide  is  added,  followed  by  a  distinct  excess  of 
a  10  per  cent,  solution  of  copper  sulphate.  The  solution  is 
allowed  to  stand  5  to  10  minutes  at  70  or  80°  C.  to  coagulate 
the  cuprous  thiocyanate.  It  is  then  filtered  and  the  precipitate 
washed  with  boiling  water  till  the  washings  give  no  coloration 
with  dilute  potassium  ferrocyanide.  The  residue  is  digested 
at  30  to  40°  C.  with  25  cubic  centimeters  of  a  4  per  cent,  solu- 
tion of  sodium  hydroxide  (free  from  chloride)  and  filtered. 
To  the  cold  filtrate  are  added  5  cubic  centimeters  of  nitric  acid 
(50  per  cent,  strength  and  free  from  oxides  of  nitrogen)  fol- 
lowed by  i  cubic  centimeter  of  a  saturated  solution  of  iron 
alum.  The  solution  is  then  filtered  from  separated  organic 
matter,  if  necessary,  and  titrated  with  N/io  silver  nitrate. 

Thiocyanate: — 2.  Ferrocyanide  present — 50  cubic  centime- 
ters of  the  liquor  are  slightly  acidified  with  sulphuric  acid,  and 
ferric  alum  solution  added  in  sufficient  quantity  to  impart  a 
decided  red  coloration.  The  solution  is  then  warmed  to  60° 
C.,  filtered  from  Prussian  blue,  and  washed  with  water  con- 
taining sodium  sulphate.  The  filtrate  is  finally  treated  as  in 
(i)  above. 

Sulphate : — 250  cubic  centimeters  of  liquor  are  concentrated 
to  about  10  cubic  centimeters  on  the  water  bath,  2  cubic  centi- 
meters of  strong  hydrochloric  added,  and  the  evaporation  con- 
tinued to  dryness.  The  residue  is  extracted  with  water  and 
the  filtered  solution  made  up  to  250  cubic  centimeters.  One 
hundred  cubic  centimeters  of  this  solution  are  acidified  with 
hydrochloric  acid,  heated  to  boiling  and  barium  chloride  added. 
After  standing  over  night,  the  precipitate  is  filtered  off  and 
weighed. 

Total  Sulphur: — 50  cubic  centimeters  of  liquor  (100  cubic 
centimeters  if  weak)  are  slowly  dropped  into  an  excess  of 


149 

bromine  (free  from  sulphur)  covered  by  water  moderately 
acidified  with  hydrochloric  acid.  The  oxidized  solution  is 
evaporated  to  dryness  on  the  water  bath,  filtered,  cooled,  and 
made  up  to  250  cubic  centimeters.  One  hundred  cubic  centi- 
meters are  precipitated  with  barium  chloride  in  the  usual  way. 

Sulphite  and  Thiosulphate : — Sulphur  present  as  sulphate, 
and  thiosulphate,  is  found  by  subtracting  from  the  total  sul- 
phur that  present  as  sulphate,  thiocyanate,  and  sulphide. 

Ferrocyanide : — To  250  cubic  centimeters  of  liquor,  acidified 
slightly  with  sulphuric  acid,  ferric  alum  solution  is  added  in 
sufficient  excess  to  impart  a  deep  red  coloration.  The  mixture 
is  then  heated  to  60°  C.  and  filtered,  the  filtrate  being  returned 
to  the  filter  if  necessary  until  a  little  of  it  shows  no  blue  color 
after  adding  mercuric  chloride.  The  precipitate  is  washed 
2  or  3  times  with  water  containing  Na2SO4.  The  filter  and 
precipitate  are  then  boiled  for  5  minutes  with  10  cubic  centi- 
meters of  N  sodium  hydroxide,  and  the  solution  diluted  to 
150  cubic  centimeters;  15  cubic  centimeters  of  3N  magnesium 
chloride  are  then  added  to  the  boiling  solution  slowly  with 
continual  shaking  in  order  to  get  a  milky  precipitate  of 
magnesium  hydrate.  This  is  then  boiled  again  and  100  cubic 
centimeters  of  boiling  N/io  mercuric  chloride  added  and  the 
boiling  continued  for  5  to  10  minutes.  The  flask  is  then  con- 
nected to  a  condenser  dipping  into  a  receiver  containing  25 
cubic  centimeters  N  sodium  hydroxide.  Thirty  cubic  centi- 
meters of  4N  sulphuric  acid  is  run  from  a  stoppered  funnel 
into  the  flask,  and  the  contents  distilled  for  20  to  30  minutes, 
when  the  whole  of  the  hydrocyanic  acid  is  obtained  in  the 
receiver.  The  distillate  is  then  titrated  with  N/io  silver  ni- 
trate, after  addition  of  a  little  potassium  iodide. 

Hydrocyanic  Acid: — 50  cubic  centimeters  of  the  liquor  are 
added  to  an  excess  (50  to  100  cubic  centimeters)  of  a  satu- 
rated solution  of  lead  nitrate  contained  in  the  distillation  flask 
of  the  apparatus  for  determining  free  and  fixed  ammonia. 
The  mixture  is  distilled  into  25  cubic  centimeters  of  N  sodium 
hydroxide  into  which  the  exit  tube  of  the  condenser  dips. 
Thirty  to  40  minutes  gentle  boiling,  at  which  time  about  50 


cubic  centimeters  of  liquid  will  have  been  distilled,  is  usually 
sufficient.  Frothing  is  liable  to  occur  and  the  flask  should  be 
heated  therefore  very  carefully.  At  the  end  of  the  distillation 
a  current  of  air  is  passed  through  the  apparatus  for  a  short 
time,  to  ensure  the  removal  of  the  hydrocyanic  acid.  The 
distillate  is  diluted  to  400  cubic  centimeters,  a  crystal  of 
potassium  iodide  added  and  the  solution  titrated  with  N/io 
silver  nitrate. 

Rapid  Method  for  Estimation  of  Carbon  Dioxide  and 
Hydrogen  Sulphide. 

In  following  the  operation  of  apparatus  in  which  a  portion 
of  the  foul  gases  (carbon  dioxide  and  hydrogen  sulphide)  are 
driven  off  from  the  liquor  by  heat,  it  is  desirable  to  be  able  to 
determine  those  gases  rapidly.  For  the  purpose,  the  methods 
of  the  Alkali  Inspector  given  above  are  too  time-consuming. 
The  following  method  is  much  more  rapid  and  sufficiently 
accurate  for  control  purposes. 

Ammoniacal  Solution  of  Calcium  Chloride: — Dissolve  100 
grams  of  calcium  carbonate  with  hydrochloric  acid,  after  add- 
ing a  little  water.  Make  alkaline  with  ammonia.  Dissolve  any 
precipitate  that  forms  with  hydrochloric  acid,  and  again  make 
alkaline.  Continue  this  process  of  redissolving  the  precipitate 
till  the  solution  finally  remains  clear  on  adding  an  excess  of 
ammonia.  Make  the  solution  up  to  one  liter. 

Barium  Hydroxide  Solution: — Put  80  grams  of  good  pure 
barium  hydroxide  in  2  liters  of  water,  and  dissolve  as  much 
of  it  as  possible.  After  settling  filter  into  another  bottle. 

Normal  sulphuric  acid  and  tenth-normal  iodine  solutions 
are  also  needed. 

In  the  process  which  is  being  examined,  it  is  very  likely  that 
the  volume  of  the  liquor  will  have  changed  between  the  inlet 
and  outlet  of  the  apparatus  by  the  addition  of  steam  or  water. 
It  is  therefore  more  informing  to  report  the  foul  gases  present 
as  a  ratio  of  the  equivalent  of  the  free  ammonia  also  present. 
A  determination  of  the  latter  must  therefore  be  made  by  direct 
titration. 


Free  Ammonia : — Pipette  10  cubic  centimeters  of  liquor,  add 
50  cubic  centimeters  of  water,  and  titrate  with  normal  sul- 
phuric acid,  with  methyl  orange  indicator. 

Carbon  Dioxide  and  Hydrogen  Sulphide: — In  the  distilling 
flask  of  the  "total  ammonia"  apparatus,  put  200  cubic  centi- 
meters of  water,  and  10  cubic  centimeters  each  of  liquor,  am- 
moniacal  calcium  chloride,  and  strong  (0.900  S.  G.)  ammonia. 
In  a  250  cubic  centimeter  flask  to  serve  as  a  receiver,  put  20 
cubic  centimeters  of  barium  hydroxide  solution,  10  cubic  centi- 
meters of  strong  ammonia  and  fill  with  water  to  one-half  inch 
from  the  bottom  of  the  neck. 

The  object  of  adding  ammonia  to  the  distilling  flask  is  to 
keep  the  contents  strongly  ammoniacal  during  the  distillation, 
as  otherwise  some  of  the  calcium  carbonate  formed  will  be 
decomposed  with  loss  of  carbon  dioxide.  The  object  of  add- 
ing barium  hydroxide  to  the  receiver  is  merely  to  show  the 
possible  presence  of  carbon  dioxide  in  the  distillate,  which  will 
occur  in  the  distillation  is  conducted  too  long  and  the  flask 
contents  cease  to  be  sufficiently  ammoniacal.  The  barium  hy- 
droxide solution  almost  always  shows  a  slight  scum,  due  to 
carbonic  acid  in  the  air,  which  must  not  be  mistaken  for  car- 
bonic acid  distilled  over. 

Distil,  slowly  at  first  but  with  a  larger  flame  as  soon  as  the 
liquid  in  the  flask  commences  to  boil,  and  continue  the  dis- 
tillation for  5  minutes  after  increasing  the  flame.  This  length 
of  distillation  will  distil  off  the  hydrogen  sulphide  without  de- 
composing the  calcium  carbonate.  The  residue  in  the  flask 
may  be  tested  with  lead  acetate  paper  to  show  the  removal  of 
hydrogen  sulphide. 

Transfer  the  liquid  in  the  receiver  to  a  600  cubic  centimeter 
beaker  and  dilute  to  about  500  cubic  centimeters.  Add  3 
drops  methyl  orange,  acidify  with  hydrochloric  acid,  add  5 
cubic  centimeters  of  starch  solution  and  titrate  with  tenth- 
normal  iodine. 

Filter  the  liquid  in  the  distilling  flask  through  a  close  grained 
filter,  wash  thoroughly  with  water,  and  dissolve  the  precipitate 
in  15  cubic  centimeters  of  normal  sulphuric  acid.  The  best 


152 

way  to  do  this  is  to  run  the  acid  into  the  washed  distillation 
flask,  to  dissolve  the  precipitate  which  lodges  there,  and  then 
transfer  it  to  a  beaker  into  which  is  put  the  filter  paper  con- 
taining the  main  portion  of  the  precipitate.  Stir  well,  boil, 
cool  and  titrate  back  with  ammonia  solution,  using  cochineal 
as  indicator. 

Since  normal  and  tenth-normal  solutions  are  used  through- 
out, the  ratio  of  the  normal  acid  used  by  the  calcium  carbonate 
to  that  used  in  titrating  the  free  ammonia,  will  show  at  once 
what  portion  of  the  ammonia  may  be  considered  to  be  com- 
bined with  carbonic  acid  as  the  normal  carbonate.  The  same 
is  true  for  the  titration  of  hydrogen  sulphide  by  iodine,  with 
allowance  for  the  fact  that  the  iodine  solution  is  tenth-normal. 

Ammonium  Sulphate. 
MOISTURE. 

Approximately  10  grams  of  the  salt  are  dried  at  105°  C.  to 
constant  weight. 

FREE  ACID. 

The  dry  salt  from  the  moisture  determination  of  approxi- 
mately 10  grams  of  a  fresh  sample  is  dissolved  in  about  200 
cubic  centimeters  of  water.  A  drop  or  two  of  methyl  orange 
or  sodium  alizarin  sulphonate  is  added  and  the  free  acid  de- 
termined by  titration  with  N/io  sodium  hydroxide  solution. 

AMMONIA. 

Ten  grams  are  dissolved  in  water  and  diluted  to  i  liter.  An 
aliquot  of  100  cubic  centimeter  is  taken  for  the  determination 
of  ammonia.  This  is  placed  with  100  cubic  centimeters  of 
water  in  a  Kjeldahl  distilling  flask;  10  cubic  centimeters  of 
30  per  cent,  caustic  soda  are  added  with  a  piece  of  granu- 
lated zinc  and  the  ammonia  distilled  over  into  80  cubic  centi- 
meters of  N/5  sulphuric  acid.  The  excess  acid  is  found  by 
titration,  etc.,  using  sodium  alizarin  sulphonate  or  cochineal 
as  indicator. 


153 

TARRY  MATTER. 

Fifty  grams  of  salt  are  dissolved  in  cold  water  and  filtered 
on  a  Gooch  crucible  which  is  dried  at  70°  C.  The  tar  is  ex- 
tracted with  ether  and  the  ethereal  extract  is  evaporated  in  a 
tared  dish.  The  weight  of  dry  extract  is  taken  as  total  organic 
matter. 

NAPHTHALENE. 

The  above  weighed  tarry  extract  is  dissolved  in  cold  alcohol 
and  an  equal  weight  of  picric  acid  also  in  alcoholic  solution 
is  added.  The  naphthalene  picrate  is  then  filtered  off,  dried 
at  100°  C.  and  weighed. 

Naphthalene  picrate  X  0.3586  =  naphthalene. 

PYRIDINE. 

To  a  filtered  solution  of  50  grams  of  sale  in  150  cubic  centi- 
meters of  water  in  a  distilling  flask  is  added  about  20  cubic 
centimeters  of  normal  caustic  soda,  sufficient  to  make  it  slightly 
alkaline,  but  not  enough  to  decompose  it.  Distil  into  100  cubic 
centimeters  of  water.  Nearly  neutralize  with  hydrochloric 
acid  and  redistil  into  30  cubic  centimeters  of  water  until  70 
cubic  centimeters  have  come  over.  Make  up  the  distillate  to 
a  volume  of  150  cubic  centimeters,  add  6  drops  of  phenol- 
phthalein,  and  then  run  in  normal  acid  till  the  pink  color  has 
just  disappeared.  Then  add  0.13  cubic  centimeter  more  of 
acid  and  read  the  burette.  Add  i  drop  of  methyl  orange  and 
titrate  to  a  pink  color.  Each  cubic  centimeter  of  acid  used 
after  adding  the  methyl  orange  equals  0.079  gram  pyridine. 

THIOCYANATES— PINK  COLOR. 

To  a  filtered  solution  of  100  grams  of  salt,  copper  sulphate 
and  sulphurous  acid  are  added  and  the  solution  gently  warmed. 
After  settling,  the  copper  thiocyanate  is  filtered  off  and  washed 
free  from  copper  salts  as  shown  by  testing  the  washings  with 
potassium  ferrocyanide.  The  precipitate  is  then  dissolved  in 
nitric  acid,  water  added,  and  the  solution  boiled  for  several 


154 

minutes.  The  copper  is  determined  in  the  solution  as  the 
oxide  by  precipitation  with  sodium  hydroxide;  or  by  elec- 
trolysis. The  weight  of  copper  X  i-*974  equals  equivalent 
amount  of  NH4SCN. 

FERRO  FERRICYANIDE— BLUE  COLOR. 

One  hundred  grams  of  salt  are  dissolved  in  hot  water  and 
filtered  on  a  folded  filter  in  a  hot  water  funnel.  Wash  with 
hot  water  until  free  from  sulphates.  The  residue  and  filter 
are  put  into  a  flask  with  about  50  cubic  centimeters  of  water, 
shaken  and  boiled  to  separate  the  residue  from  the  filter  as 
much  as  possible.  To  the  contents  of  the  flask  N/5<D  sodium 
hydroxide  solution  is  added  little  by  little  until  the  blue  is 
entirely  decomposed,  which  is  hastened  by  having  the  contents 
of  the  flask  warm.  While  constantly  shaking  and  heating,  the 
excess  sodium  hydroxide  is  titrated  with  N/5O  acid.  The 
heating  is  quite  necessary  for  even  in  the  presence  of  an  alkali, 
the  greenish  color  formed  by  the  decomposition  of  the  blue 
lasts  only  a  short  time. 

The  end  point  is  reached  when  the  dark  green  color  in  the 
solution  first  appears. 

One  cubic  centimeter  N/5O  NaOH  equals  0.001431  gram 

Fe4Fe,(CY«).. 

ARSENIC. 

Dissolve  100  grams  of  salt  in  water  and  filter.  The  arsenic 
will  be  on  the  filter  as  sulphide.  Dissolve  the  sulphide  by  hot 
digestion  with  sodium  sulphide,  using  as  little  as  possible.  Fil- 
ter and  wash  by  stirring  and  pressure  using  slightly  alkaline 
H2S  water.  Evaporate  filtrate  to  dryness  in  25  to  50  cubic 
centimeters  hydrochloric  acid  (2  acid  to  I  water)  and  add  a 
small  crystal  of  tartaric  acid.  Precipitate  the  arsenic  from 
the  cold  solution  with  H2S,  allow  to  settle  for  a  short  time, 
filter  on  an  asbestos  felt  and  wash  with  acid  of  the  same 
strength.  This  separates  the  arsenic  from  any  traces  of  an- 
timony that  may  be  present  from  hard  lead  and  from  traces  of 
tin  which  are  sometimes  present  in  distilled  water  which  has 
been  condensed  in  a  tin  worm. 


155 

Place  the  felt  with  the  arsenic  sulphide  in  a  beaker,  digest 
on  a  steam  plate  with  red  fuming  nitric  acid,  dilute  the  solution 
with  \y2  parts  of  water  and  filter  out  the  asbestos,  and  evap- 
orate to  dryness  with  o.i  to  0.5  gram  of  sodium  nitrate. 

Dissolve  the  residue  in  5  cubic  centimeters  of  cold  water 
with  10  drops  of  HC1  and  o.i  gram  tartaric  acid.  Filter  into 
a  small  beaker  and  wash  with  as  little  water  as  possible  with 
a  fine  jet. 

Make  slightly  alkaline  with  ammonia.  The  solution  should 
be  clear  and  not  more  than  1  1  cubic  centimeters  in  volume. 

Add  3  cubic  centimeters  magnesia  mixture,  make  up  to  20 
cubic  centimeters  with  strong  ammonia  and  stir  5  minutes. 
Allow  to  stand  over  night  and  filter  on  a  small  filter,  aiding  the 
transfer  of  the  precipitate  within  the  filtrate.  Wash  free  from 
chlorine  with  a  fine  jet  of  ammonia  (i  to  3  of  water)  dry  in  an 
oven,  remove  the  salt  and  place  filter  in  a  porcelain  crucible. 
Add  a  few  drops  of  acid  ammonium  nitrate  solution  (satu- 
rated), char  carefully  and  repeat  treatment  until  paper  is  con- 
sumed without  any  perceptible  odor  of  arsenic.  Transfer  the 
remainder  of  the  precipitate  and  ignite  at  a  full  red  heat  to 
constant  weight.  Weigh  as  Mg2As2O7. 


Sampling. 

A  large  shovelful  is  taken  from  each  cart-load  during  the 
unloading  of  a  car,  and  put  into  a  covered  barrel.  This 
sample  is  broken  down  rapidly  to  ^-inch  size,  reduced  by 
quartering  to  2  quarts,  sealed  up  in  an  air-tight  container  and 
sent  to  the  laboratory.  In  the  laboratory  it  is  ground  to  a  fine 
powder  preferably  in  a  ball  mill  to  avoid  absorption  of  moist- 
ure and  carbon  dioxide,  and  put  in  rubber  stoppered  weigh- 

ing tubes. 

i 

DETERMINATION  OF  CALCIUM  OXIDE. 

Five  grams  of  the  finely  ground  lime  is  weighed  into  a  500 
cubic  centimeter  graduated  flask.  Ten  cubic  centimeters  of 
alcohol  are  added,  to  prevent  the  later  caking  of  calcium  su- 


156 

crate,  and  the  flask  is  filled  up  to  the  mark  with  a  10  per  cent, 
cane-sugar  solution.  It  is  shaken  frequently  over  a  4-hour 
period,  or  longer.  The  solution  is  then  filtered,  an  aliquot  of 
100  cubic  centimeters  taken  and  titrated  with  normal  hydro- 
chloric acid,  using  methyl  orange  indicator. 

Multiply  five  times  the  cubic  centimeters  of  acid  used  by 
0.02804.  Divide  by  the  amount  of  lime  taken.  The  result  is 
the  per  cent,  of  calcium  oxide. 

CYANOGEN. 

Moisture. 
Dry  30  grams  oxide  for  nine  (9)  hours  at  50°  to  60°  C. 

Extraction  of  Blue. 

Grind  the  dried  oxide  so  that  it  passes  through  an  8o-mesh 
sieve.  Weigh  out  10  grams  of  this  and  introduce  into  a  250 
cubic  centimeter  flask.  Add  50  cubic  centimeters  of  a  10  per 
cent,  caustic  potash  solution  and  let  stand  for  15  to  16  hours 
at  ordinary  temperature,  shaking  frequently.  At  the  end  of 
this  time,  make  up  to  225  cubic  centimeters  (5  cubic  centi- 
meters for  the  oxide).  Shake  vigorously  and  filter  through 
a  dry  filter.  Take  100  cubic  centimeters  of  the  filtrate  and 
run  it  into  a  boiling  solution  of  ferric  chloride — 50  cubic  cen- 
timeters. This  ferric  chloride  solution  consists  of  60  grams 
ferric  chloride  and  100  cubic  centimeters  HC1  made  up  to 
1,000  cubic  centimeters.  After  the  blue  settles  a  little,  filter 
and  wash  with  boiling  water,  until  the  blue,  together  with  the 
filter  paper  is  put  into  a  beaker  and  25  cubic  centimeters  of 
the  caustic  potash  solution  is  added,  and,  after  complete  de- 
composition, made  up  to  250  cubic  centimeters  and  then  filtered 
through  a  dry  filter.  Take  100  cubic  centimeters  of  this  fil- 
trate, acidify  with  10  per  cent,  sulphuric  acid  (test  with  lit- 
mus) and  add  excess  of  10  cubic  centimeters  acid.  Titrate 
with  standard  zinc  sulphate  solution,  the  operation  being  the 
same  as  in  the  standardization  of  the  zinc  solution.  From  the 
number  of  cubic  centimeters  zinc  sulphate  used,  the  value  of 
this  in  prussiate  can  be  calculated. 


157 

Calculation. — Multiply  your  standard  by  number  of  cubic 
centimeters  ZnSO4  used,  and  divide  by  1.6,  multiply  this  re- 
sult by  100.  This  gives  per  cent,  of  Prussian  blue  as 
K4Fe(CN)6  in  dry  sample. 

This  result  multiplied  by  100  minus  the  moisture  per  cent, 
gives  the  result  in  terms  of  the  undried  oxide. 

ZINC  SULPHATE  SOLUTION. 

Weigh  out  10  grams  zinc  sulphate  C.  P.  and  make  up  to  i 
liter,  after  adding  10  cubic  centimeters  concentrated  sulphuric 
acid. 

POTASSIUM  FERROCYANIDE  SOLUTION. 

Weigh  out  exactly  5  grams  potassium  ferrocyanide  (C.  P. 
and  with  exact  quantity  of  water  of  crystallization.  If  this 
is  more  or  less,  a  correction  has  to  be  made).  Make  up  to 
250  cubic  centimeters. 

STANDARDIZING  THE  ZINC  SOLUTION. 

Measure  out  25  cubic  centimeters  of  the  ferrocyanide  solu- 
tion into  a  beaker.  Add  about  50  cubic  centimeters  of  water 
and  acidify  with  10  cubic  centimeters  of  a  10  per  cent,  sul- 
phuric acid  solution.  Now  from  a  burette  run  in  the  zinc 
solution. 

As  an  indicator,  use  a  3  per  cent,  solution  of  ferric  alum, 
using  Schleichner  &  Schnell's  drop  reaction  paper  No.  601. 
One  drop  of  the  ferric  alum  solution  is  brought  on  to  the 
paper,  and  near  this  spot  a  drop  of  the  solution  being  titrated 
is  placed,  so  that  by  extension  the  two  spots  just  touch  each 
other.  The  end  point  of  the  titration  is  reached  when  the  blue 
coloration  at  the  point  where  the  two  drops  meet  does  not 
appear  for  the  space  of  I  minute.  From  the  number  of  cubic 
centimeters  of  zinc  'sulphate  solution  used,  the  value  of  this 
in  prussiate  can  be  calculated. 

In  titrating  the  oxide  solution,  acidify  the  100  cubic  centi- 
meters with  10  per  cent,  sulphuric  acid,  after  adding  methyl 
orange  No.  3  to  the  solution,  and  add  an  excess  of  10  cubic 
ii 


IS8 

centimeters  acid.  Titrate  with  the  standard  zinc  solution, 
the  operation  being  the  same  as  the  standardization  of  the  zinc 
solution. 

The  original  Knublauch  method  involved  the  use  of  copper 
sulphate. 

The  Feld-Witzeck  Method. 

Two  grams  of  the  dried  and  finely  pulverized  oxide  are 
taken  and  titrated  for  5  minutes  in  a  glass  mortar  with.i  cubic 
centimeter  of  normal  solution  of  ferrous  sulphate  and  5  cubic 
centimeters  of  eight  times  normal  solution  of  caustic  soda. 
Then  50  cubic  centimeters  of  three  times  normal  solution  of 
magnesium  chloride  are  added  with  constant  stirring,  and  the 
whole  is  washed  into  a  flask — the  volume  of  liquid  being 
brought  to  about  220  cubic  centimeters.  After  boiling  for  5 
to  10  minutes,  100  cubic  centimeters  of  boiling  decinormal 
solution  of  mercuric  chloride  are  poured  into  the  boiling  liquid, 
and  the  boiling  continued  for  10  minutes.  The  flask  is  then 
connected  with  the  condenser,  30  cubic  centimeters  of  four 
times  normal  sulphuric  acid  are  added,  and  the  liquid  is  dis- 
tilled for  20  to  30  minutes.  The  distillate  is  collected  in  20 
cubic  centimeters  of  twice  normal  solution  of  caustic  soda.  If 
it  is  cloudy,  0.5  gram  of  lead  carbonate  is  added  to  it  in  a 
measuring  flask,  which  is  filled  to  the  mark,  and  an  aliquot 
portion  is  taken  for  the  titration,  after  the  precipitate  has  been 
filtered  off. 

The  titration  is  carried  out  according  to  Liebig's  method 
with  decinormal  solution  of  silver  nitrate  and  the  addition  of 
"5  cubic  centimeters  of  one-fourth  normal  solution  of  potassium 
iodide.  The  appearance  of  a  yellowish  milky  cloudiness  indi- 
cates the  end  of  the  reaction.  (Journal  of  Gas  Lighting  & 
Water  Supply,  Aug.  3,  1915,  p.  244.) 

Apparatus  for  Distillation. — A  round  bottom  flask  is  pro- 
vided with  a  double  bored  rubber  stopper  which  contains  a 
separatory  funnel  and  distilling  column.  The  latter  is  con- 
nected with  a  condenser  which  dips  into  an  Erlenmeyer  flask 


159 

also  provided  with  a  double  bored  rubber  stopper,  the  second 
hole  is  connected  with  a  3-bulb  tube  containing  sodium  hy- 
droxide. ( Allen- s  Commercial  Organic  Analysis,  Vol.  VII, 

P-  521-} 

The  Committee  recommends  the  use  of  the  Feld-Witzeck 

Method. 


CHAPTER  HI. 

IMPURITIES  IN  GAS. 

DETERMINATION  OF  HYDROGEN  SULPHIDE. 

The  hydrogen  sulphide  is  determined  by  leading  the  gas 
through  a  suitable  absorption  apparatus  containing  a  solution 
of  lead  nitrate.  The  resulting  lead  sulphide  is  filtered  off, 
oxidized  in  a  porcelain  crucible  with  nitric  acid,  treated  with 
a  drop  of  sulphuric  acid,  evaporated  to  dryness,  ignited  and 
weighed. 

For  works  control  where  great  accuracy  is  second  and  speed 
first  consideration,  the  H2S  burette  is  the  most  widely  used 
method  and  gives  within  small  errors  best  results,  and  can  be 
recommended  as  sufficiently  accurate  for  all  practical  pur- 
poses. 

The  apparatus  employed  is  shown  in  Fig.  34.  It  consists 
of  a  burette  provided  at  the  top  with  a  2- way  and  at  the 
bottom  with  a  i-way  cock,  communicating  at  top  through  one 
of  the  outlets  with  a  10  cubic  centimeter  glass  stoppered  cyl- 
inder graduated  into  i/io  cubic  centimeter.  There  are  only 
two  graduations  on  the  burette  proper,  one  at  the  100  cubic 
centimeter  mark,  and  the  other  50  millimeters  from  the  bottom 
cock,  dividing  the  remaining  space  into  two  divisions  of  about 
5  cubic  centimeters  and  10  cubic  centimeters  respectively.  A 
levelling  bulb  is  attached  to  the  lower  cock  at  E,  and  the  burette 
mounted  on  a  stand  as  indicated. 

Chemicals. 

The  following  chemicals  are  necessary : 

1.  Standard  Iodine  Solution. — One  cubic  centimeter  of  this 
solution  should  contain  0.0017076  gram  iodine,  which  is  equiv- 
alent to  loo  grains  of  sulphur eted  hydrogen  per  100  cubic  feet 
of  gas. 

2.  Starch  Solution. — Rub  into  a  thin  paste  about  I  teaspoon- 
ful  of  wheat  starch  with  a  tablespoonful  of  water.     Pour  into 
a  pint  of  boiling  water,  stir,  allow  to  stand  until  cold,  and 


pour  off  the  clear  solution  for  use.     Make  a  fresh  solution 
every  few  days. 


FIG.  34. 


1 62 

t 

To  Make  Analysis. 

Fill  levelling  bulb  L  with  starch  solution  and  turn  cocks  so 
that  on  raising  the  levelling  bulb  the  starch  solution  will  fill 
the  burette  and  run  out  through  the  gas  inlet  tube  A.  Close 
lower  cock  C,  and  attach  rubber  tube  through  which  the  gas 
to  be  tested  is  passing  to  inlet  tube  A.  Open  lower  cock,  and 
lower  levelling  bulb  until  the  starch  solution  just  passes  the 
100  cubic  centimeter  mark  on  the  stem  of  the  burette.  Close 
lower  cock,  then  close  top  cock  F,  and  disconnect  from  gas 
supply.  Open  lower  cock  and  bring  starch  solution  to  100 
cubic  centimeter  mark  by  raising  levelling  bulb,  then  close 
lower  cock  and  open  top  cock  to  air  momentarily  to  obtain  at- 
mospheric pressure  in  the  burette.  Close  top  cock  and  by  open- 
ing lower  cock  and  lowering  the  levelling  bulb  draw  the  starch 
out  of  the  burette  down  to  the  10  cubic  centimeter  mark.  Close 
lower  cock,  place  clip  on  rubber  tubing  near  E,  and  disconnect 
levelling  bulb  from  £. 

We  now  have  100  cubic  centimeters  of  gas  measured  at 
atmospheric  temperature  and  pressure,  under  a  negative  pres- 
sure. 

Fill  graduated  cylinder  C  with  standard  iodine  solution, 
noting  reading  on  same.  Admit  iodine  solution  into  the  bu- 
rette very  gradually  through  F,  shaking  well  between  each  ad- 
dition. Continue  until  the  starch  solution  assumes  a  faint,  but 
permanent  blue  color. 

Note  reading  on  graduated  cylinder,  which  subtracted  from 
previous  reading  gives  amount  of  solution  used.  This  multi- 
plied by  100,  gives  directly  number  of  grains  of  hydrogen 
sulphide  per  100  cubic  feet  of  gas. 

Precautions. 

I.  It  will  be  found  that  even  with  gas  entirely  free  from  sul- 
phureted  hydrogen  an  appreciable  amount  of  iodine  solution 
will  be  required  to  color  the  starch  solution  a  permanent  blue. 
Therefore  a  certain  constant,  previously  determined  on  each 
fresh  bottle  of  starch  solution,  should  be  subtracted  from  all 


i63 

readings.  In  order  to  determine  this  constant,  suck  starch 
solution  into  the  burette  up  to  the  10  cubic  centimeter  mark, 
this  being  the  amount  used  in  each  determination,  close  lower 
cock  and  carefully  drop  into  the  burette  iodine  solution  from 
the  cylinder,  shaking  between  each  addition,  until  the  starch 
solution  assumes  a  permanent  blue  color.  Note  amount  of 
iodine  added,  which  will  be  about  0.2  cubic  centimeter  to  0.3 
cubic  centimeter  and  subtract  this  from  total  amount  of  iodine 
solution  required  in  each  determination. 

2.  The  blue  color  must  not  be  confused  with  the  opalescent 
milky  appearance  due  to  the  separation  of  free  sulphur,  nor 
with  a  red  color  which  will  disappear  on  shaking. 

3.  For  extremely  accurate  work,  introduce  a  correction  fac- 
tor for  temperature  and  pressure,  bringing  the  gas  to  60°  F 
and  30". 

In  special  cases  where  the  highest  accuracy  is  required  and 
time  can,  therefore,  be  no  factor,  the  following  method  is  the 
most  suitable : 

The  gas  to  be  tested  is  first  purified  from  such  impurities  as 
may  interfere  with  the  work,  such  as  tar,  by  passing  it  through 
a  U-tube  filled  with  cotton  and  then  into  a  gas  wash  bottle 
containing  an  ammoniacal  solution  of  silver  nitrate.  (It  is  best 
to  use  two  bottles  in  series  to  prevent  any  H2S  to  go  by  when 
the  first  bottle  should  become  saturated  by  a  high  H2S  content 
in  the  gas,  stopping  the  operation  when  the  second  solution  is 
showing  precipitate  of  silver  sulphide.)  The  ammonia  ab- 
sorbed by  the  gas  from  the  train  is  removed  by  another  bottle 
containing  H2SO4  before  entering  the  meter.  Where  insuffi- 
cient gas  pressure  exists  it  is  best  to  use  suction  to  pull  the 
gas  through.  The  solution  and  precipitated  Ag2S  etc.  is  next 
transferred  to  a  beaker  and  filtered  and  washed.  The  silver 
acetylene  formed  is  next  decomposed  by  filling  the  filter  with 
diluted  HC1,  forming  silver  chloride  and  acetylene ;  again  wash 
with  water  and  remove  the  silver  chloride  with  dilute  NH^OH 
and  again  with  water. 

The  filter  and  contents  are  next  placed  in  a  Rose  crucible, 
dryed  and  burned.  After  all  the  filter  paper  has  been  burned 


164 


and  the  sulphide  roasted,  the  silver  is  reduced  in  a  stream  of 
hydrogen  to  metallic  silver.  From  the  weight  of  the  metallic 
silver  the  H2S  is  calculated  by  multiplying  the  weight  with 
0.1578  or  with  0.14875  for  sulphur. 


FIG.  35. 

Another  quicker  although  not  quite  as  accurate  method  has 
been  in  use  in  various  modifications.  It  is  based  on  the  method 
of  determining  sulphur  in  steel.  The  gas  freed  from  tar  by 
passing  it  through  cotton  is  bubbled  through  an  ammoniacal 
solution  of  cadmium  chloride  contained  in  a  gas  washing 
bottle  using  a  graduated  aspirating  bottle  for  measuring  the 
gas  or  a  meter.  The  operation  is  as  follows : 

To  the  gas  outlet  by  means  of  a  short  rubber  tube  connect 
a  U-tube  filled  with  cotton,  connect  this  with  two  gas  washing 
bottles  (200  cubic  centimeters  capacity),  containing  50  cubic 


centimeters  of  an  ammoniacal  solution  of  cadmium  chloride,  in 
series.  If  a  meter  is  used  for  measuring  the.  gas  another  bottle 
containing  dilute  sulphuric  acid,  to  remove  the  ammonia  from 
the  gas  before  entering  the  meter,  must  be  placed  behind  the 
absorption  bottles.  This  can  be  omitted  where  a  graduated 
aspirating  bottle  is  used.  This  bottle  (see  Fig.  35)  is  gradu- 
ated by  filling  it  with  water  to  a  mark  scratched  on  the  glass  L 
in  the  stopper  at  the  top,  the  water  is  next  drawn  out  through 
the  bottom  stopper  also  fitted  with  a  glass  L  and  closed  with 
a  piece  of  rubber  tubing  and  pinch-cock.  3,537.5  cubic  centi- 
meters =  to  y%  cubic  foot  of  the  water  are  drawn  off  and  the 
bottle  marked.  This  is  best  accomplished  by  having  a  2-hole 
stopper  at  the  bottom,  the  second  hole  being  fitted  with  a  glass 
tubing  bent  short  at  right  angles  and  reaching  to  the  top. 
The  bottle  being  perfectly  level,  the  second  mark  is  made  on 
this  tube  insuring  more  accurate  measuring.  Where  a  meter 
is  used  from  o.i  to  0.15  cubic  foot  of  gas  are  passed.  In  both 
cases  the  gas  should  be  passed  at  a  very  slow  speed,  not  more 
than  0.5  cubic  foot  per  hour. 

The  contents  of  the  washing  bottles  are  next  transferred  to 
a  600  cubic  centimeter  beaker,  the  bottles  first  washed  with  dis- 
tilled water  and  then  with  a  little  dilute  hydrochloric  acid,  suffi- 
cient dilute  HC1  added  to  the  beaker  to  make  acid,  indicated  by 
clearing  of  solution,  starch  solution  added  and  titrated  with 
standardized  iodine  solution,  and  the  H2S  calculated  from  the 
iodine  used. 

Qualitative  Test. 
For  qualitative  test  the  following  method  is  in  general  use : 

A  strip  of  white  filter  paper  is  dipped  in  a  solution  containing 
5  per  cent,  by  weight  of  lead  acetate,  the  excess  solution  being 
removed  from  the  test  paper  with  a  blotter.  The  paper  is  ex- 
posed while  moist  for  I  minute  to  a  current  of  gas  flowing  at 
the  rate  of  approximately  5  cubic  feet  per  hour  in  an  apparatus 
as  shown  in  Fig.  31  and  described  below,  or  in  other  similar 
apparatus. 


1 66 


The  gas  may  be  considered  free  from  hydrogen  sulphide  if 
the  paper  thus  exposed  is  not  distinctly  darker  than  another 
paper  moistened  with  the  same  solution  but  not  exposed  to 
the  gas. 


!      i 

!        1 

V 

fpn 

i      j 

TT 


FIG.  36.— Apparatus  for  exposing  test  paper. 

The  apparatus  for  exposing  the  paper  as  shown  in  Fig.  36 
is  made  from  a  cylindrical  gas  chimney  8  inches  long,  and  1^4 
inches  in  diameter.  The  pillar  of  a  gas  burner  from  which  the 
lava  tip  has  been  removed  is  inserted  through  the  lower  stop- 
per, and-  a  small  glass,  i  to  i^  inches  in  diameter  is  sup- 
ported above  the  pillar  to  prevent  the  gas  from  impinging 
directly  on  the  test  paper.  The  watch  glass  may  be  supported 
on  three  glass  pegs,  ^  to  i  inch  high,  being  held  in  place  with 
small  bits  of  wax.  The  gas  is  burned  from  an  ordinary  open 


:67 

flame  burner  on  the  upper  stopper,  this  burner  being  so  selected 
that  it  will  pass  5  cubic  feet  per  hour  at  the  ordinary  pressure 
of  the  gas  supply.  The  test  paper  is  hung  on  a  glass  hook  so 
that  it  is  held  midway  between  the  watch  glass  and  the  bottom 
of  the  upper  stopper. 

This  apparatus  may  be  attached  permanently  to  a  wall 
bracket,  or  a  Bunsen  burner  may  be  inserted  through  the  lower 
stopper  in  place  of  the  pillar  so  that  the  apparatus  can  con- 
veniently be  attached  at  any  outlet  with  a  rubber  hose. 


AMMONIA. 
Methods  of  Operation. 

The  apparatus  as  shown  in  Fig.  37  consists  of  two  all  glass 
modified  Woulff  bottles.  These  should  be  placed  before  the 
governor  and  meter  if  the  ammonia  determination  is  made  in 
connection  with  the  sulphur  determination. 

Place  in  the  absorption  apparatus  an  accurately  measured 
portion  (about  25  cubic  centimeters)  of  a  standard  solution  of 
sulphuric  acid  prepared  as  directed  below,  and  add  2  drops  of 
the  indicator  solution.  The  acid  should  be  measured  from  a 
pipette  or  a  burette  and  may  then  be  diluted  with  the  distilled 
water  until  the  volume  is  obtained  which  gives  the  best  opera- 
tion with  the  particular  apparatus  in  use.  Connect  the  appar- 
atus writh  the  gas  supply,  and  with  a  meter  on  the  outlet  of  the 
bottle  pass  the  gas  to  be  tested,  at  the  rate  of  0.5  to  0.6  cubic 
foot  per  hour,  for  2  to  5  hours,  according  to  conven- 
ience and  accuracy  required.  Somewhat  greater  accuracy  is 
secured  by  the  longer  test.  When  the  requisite  amount  of  gas 
has  passed,  the  supply  is  shut  off  and  the  color  of  the  solu- 
tion noted  to  determine  whether  the  acid  has  been  neutralized, 
as  shown  by  the  indicator.  If  neutralized,  add  more  H2SO4 
to  make  slightly  acid.  The  acid  remaining  unneutralized  is 
determined  as  follows :  The  content  of  the  apparatus  is  rinsed 
into  a  beaker  with  distilled  water,  using  the  smallest  amount 


i68 


possible  to  secure  complete  removal  of  the  acid,  and  the  solu- 
tion is  titrated  with  a  standard  solution  of  sodium  hydroxide. 

A  solution  of  sodium  alizarin  sulphonate  is  recommended 
as  an  indicator.  The  solution  of  sodium  alizarin  sulphonate 
for  use  is  made  by  dissolving  I  gram  of  the  material  in  100 
cubic  centimeters  of  water  and  filtering  off  the  undissolved 


FIG.  37. 


portion.  In  titrating,  the  end  point  is  reached  when  the  color 
changes  from  greenish  yellow  to  light  brown.  The  color 
further  changes  to  red,  but  the  first  change  is  the  proper  one 
for  this  work.  The  change  is  sharp. 

Preparation  of  Solutions. 
The   sulphuric   acid   may   be   conveniently   made   of    such 


i6g 

strength  that  I  cubic  centimeter  neutralizes  approximately 
0.005  gram  of  ammonia,  and  its  exact  strength  is  determined 
by  standardization.  To  2  liters  of  distilled  water  add  between 
1.25  and  1.50  cubic  centimeters  of  pure  concentrated  sulphuric 
acid  and  mix  thoroughly  by  shaking.  This  solution  must  be 
carefully  preserved  in  a  glass  stoppered  bottle  to  avoid  con- 
tamination and  evaporation.  For  the  standardization  of  the 
acid  a  50  cubic  centimeter  portion  is  accurately  measured  into 
a  400  cubic  centimeter  beaker,  diluted  to  250  cubic  centimeters 
and  treated  with  10  per  cent,  barium  chloride  solution  in  the 
manner  already  given.  The  weight  of  barium  sulphate  (in 
grams)  obtained  by  this  process  is  multiplied  by  2.25  and  then 
divided  by  the  number  of  cubic  centimeters  of  solution  taken 
as  sample.  The  result  is  then  expressed  in  grains  of  ammonia 
equivalent  to  I  cubic  centimeter  of  the  acid. 

The  sodium  hydroxide  solution  for  titrating  the  excess  of 
the  acid  is  prepared  by  dissolving  approximately  1.8  grams  of 
sodium  hydroxide  in  2  liters  of  water  and  mixing  thoroughly. 
To  obtain  the  ratio  of  the  acid  to  the  alkali,  measure  out  the 
same  amount  of  acid  as  is  ordinarily  titrated  in  a  determina- 
tion and  add  distilled  water  until  the  volume  of  solution  is 
about  equal  to  that  obtained  in  washing  out  the  apparatus 
after  a  determination,  add  2  drops  of  indicator  solution  and 
complete  the  titration  with  the  alkali.  For  convenience  the 
strength  of  the  alkali  may  be  made  equivalent  to  the  acid  by 
dilution  or  further  addition  of  alkali. 


TOTAL 

The  referee's  form  of  apparatus  is  recommended  on  account 
of  its  wide  use  and  general  ease  of  manipulation.  The  ap- 
paratus is  shown  in  Fig.  38. 

The  entire  apparatus  consists  of  a  pressure  governor,  U 
water  gauge,  meter  and  sulphur  apparatus;  these  being  con- 
nected in  the  order  given.  If  the  gas  used  for  the  sulphur  tests 
is  also  used  for  the  ammonia  test,  the  ammonia  absorber  is 


connected  between  the  source  of  the  gas  supply  and  the  pres- 
sure governor.  For  connecting  the  various  parts  of  the  appa- 
ratus rubber  tubing  is  not  satisfactory.  It  is  usually  most  con- 
venient to  make  permanent  connections  from  governor  to 
gauge,  gauge  to  meter,  and  meter  to  burner;  these  can  be  of 
glass  tubing  with  rubber  connections  wired  on,  except  the 


-. 


FIG.  38. 


connection  of  meter  to  burner.  For  the  latter  it  is  best  to 
braze  or  screw  a  metal  tube  to  the  burner  inlet  (about  6  to  8 
inches  is  a  convenient  length)  so  that  if  the  burner  strikes 
back  during  a  test  the  connection  is  not  broken  at  the  base  of 
the  burner  and  gas  allowed  to  escape  or  take  fire  at  this  point. 
The  meter  and  governor  used  may  be  of  either  the  wet  or  dry 
type.  'The  usual  precautions  as  to  levelling  and  proper  adjust- 
ment should,  of  course,  be  observed.  The  pressure  on  the 
governor  should  be  so  adjusted  once  for  all  that  when  the  gas 
is  turned  on  full  at  the  supply  cock  the  burner  will  pass  gas 
at  the  desired  rate. 


I/I 

The  connection  between  meter  and  burner,  as  well  as  the 
meter  itself,  should  be  frequently  tested  to  show  the  absence 
of  leaks.  Any  leaks,  even  very  small  ones,  may  cause  appre- 
ciable errors  in  the  test,  since  the  rate  of  gas  consumption  is 
small. 

Method  of  Operation. 

After  all  connections  and  adjustments  of  the  apparatus  have 
been  made  the  gas  should  be  burned  from  the  apparatus  for 
several  hours  to  saturate  the  meter  and  governor  water  and 
to  purge  the  connections.  Before  each  test  the  line  may  be 
purged  in  this  way  by  burning  the  gas  for  about  a  half-hour,  a 
burner  which  will  pass  5  cubic  feet  or  more  per  hour  being 
substituted  for  the  regular  test  burner. 

When  the  line  is  thus  purged,  the  regular  burner  is  put  in 
place  and  ammonium  carbonate  placed  on  the  burner.  As 
much  ammonium  carbonate  is  used  as  will  find  place  about  the 
burner  pillar.  The  ammonium  carbonate  should  be  in  large 
lumps  which  have  been  freed  from  effervescent  portions.  It 
is  usually  desirable  to  rinse  out  condenser  and  chimney  tubes 
just  before  starting  the  test,  in  order  to  prevent  dust  which 
might  have  collected  there  between  the  tests  from  contami- 
nating the  condensate.  When  all  parts,  including  the  "flask  to 
collect  the  condensate,  are  in  place,  the  trumpet  tube  is  set 
over  the  burner  and  quickly  connected  with  the  condenser, 
the  meter  reading  being  noted  at  the  instant  the  trumpet  tube 
is  put  in  place.  This  reading  and  the  time,  meter,  tempera- 
ture, barometer  and  manometer  readings  are  recorded  in  the 
test  record. 

The  gas  is  burned  at  y2  cubic  foot  per  hour. 

If  the  sulphate  is  to  be  determined  gravimetrically,  it  is  gen- 
erally desirable  to  burn  at  least  2.y2  or  3  cubic  feet  of  gas  for 
a  test. 

When  it  is  desired  to  burn  more  than  3  cubic  feet  of  gas 
for  a  test,  it  is  necessary  to  replenish  the  supply  of  ammonium 
carbonate.  To  do  this  the  gas  is  shut  off  and  the  trumpet 
tube  allowed  to  cool  so  that  it  may  be  handled  comfortably. 


A  fresh  supply  of  carbonate  is  then  added,  the  burner  re- 
lighted, and  the  trumpet  tube  replaced  quickly.  If  more  than 
a  few  thousandths  of  a  cubic  foot  of  gas  are  burned  with  the 
trumpet  tube  off,  the  amount  so  burned  should  be  deducted 
from  the  total  used  for  the  test.  A  fresh  supply  of  carbonate 
must  be  added  in  this  manner  after  every  3  cubic  feet  of  gas 
burned  in  the  Referee's  apparatus. 

When  sufficient  gas  has  been  burned,  the  supply  is  cut  off 
and  the  apparatus  allowed  to  cool.  The  time,  meter  reading, 
meter  temperature,  and  barometer  are  recorded  again  at  the 
close  of  the  test.  The  trumpet  tube  is  then  washed  once  and 
the  condenser  four  times.  Each  portion  of  wash  water  is  50 
cubic  centimeters  and  is  added  all  at  once  to  thoroughly  flush 
the  condenser. 

The  sulphate  in  the  condensed  liquid  and  wash  water  is  de- 
termined by  precipitation  with  barium  chloride.  From  sulphate 
found  and  corrected  volume  of  gas  burned,  the  sulphur  con- 
tent of  the  gas  (in  grains  of  sulphur  per  100  cubic  feet  of  gas) 
is  calculated. 

Determination  of  Sulphate  in  the  Solution  Obtained. 

In  the  more  common  procedures  for  the  gravimetric  sul- 
phate determination,  the  precipitation  of  the  barium  sulphate 
is  made  in  nearly  neutral  solution.  This  method  may  be  used 
as  follows: 

To  the  solution  which  is  diluted  or  concentrated  to  about 
300  cubic  centimeters  add  2  or  3  drops  of  paranitrophenol  or 
methyl  orange  solution  and  neutralize  with  hydrochloric  acid, 
adding  this  solution  dropwise,  and  finally  add  2  cubic  centi- 
meters of  the  i :  i  acid  in  excess.  Heat  to  boiling,  add  10 
per  cent,  barium  chloride  solution,  boil  5  minutes,  allow  to 
stand  on  a  steam  bath  for  a  half-hour  or  longer,  filter  through 
a  good  close-grained  paper,  and  wash  with  hot  water  until  a 
few  drops  of  filtrate  collected  in  a  test-tube  no  longer  form  a 
precipitate  with  silver  nitrate.  In  a  weighed  platinum  crucible 
char  the  paper  with  low  Bunsen  flame  and  finally  ignite  until 
the  precipitate  appears  white.  Cool  the  crucible  in  a  desic- 


173 

cator  and  weigh.  The  precipitation  when  made  in  the  pres- 
ence of  a  fixed  amount  of  acid  is  always  affected  in  equal 
degree  by  the  solubility  of  the  barium  sulphate  in  the  acid. 
Under  the  conditions  given,  the  loss  from  this  source  is  negli- 
gible for  the  present  work. 

DETERMINATION  OF  NAPHTHALENE  IN  GAS. 
Absorption  of  Naphthalene  by  Picric  Acid. 

Pass  the  gas  to  be  tested  first  through  N/i  H2SO4,  next 
through  an  empty  bottle,  then  through  three  bottles  each  con- 
taining 100  to  150  cubic  centimeters  of  saturated  picric  acid 
solution  and  excess  of  undissolved  picric  acid,  (2)  and  finally 
through  a  gas  meter  for  measurement.  Stop  the  operation 
when  a  naphthalene  picrate  precipitate  begins  to  appear  in  the 
second  picric  acid  wash  bottle. 

Preparing  Benzol  Solution  of  Naphthalene-Pier  ate 
and  Picric  Acid. 

Transfer  the  picric  acid  solution  and  precipitate  to  a  liter 
separatory  funnel,  the  residues  being  washed  in  with  naphtha- 
lene-free benzol.  Shake  gently  the  funnel  contents  until  the 
precipitate  is  completely  dissolved  in  the  benzol.  Reject  the 
aqueous  layer  and  draw  the  benzol  solution  into  a  250  cubic 
centimeter  measuring  flask.  Make  up  to  the  mark  with  benzol 
and  thoroughly  mix. 

Determination  of  Total  Picric  Acid. 

Titrate  50  cubic  centimeters  of  this  solution — preferably  in 
a  200  or  250  cubic  centimeter  separatory  funnel  for  shaking  is 
necessary — with  N/5  NaOH  using  methyl  red  as  indicator. 
This  titrates  both  the  free  and  combined  picric  acid. 

If  T  =  cubic  centimeters  N/5  NaOH  required  for  this 
total  titre. 

Then  $T  =  cubic  centimeters  N/5  NaOH  required  for  total 
titre  of  the  whole  solution. 

(To  prepare  methyl  red  indicator,  dissolve  2  grams  methyl 

12 


174 

red  in  I  liter  of  a  mixture  of  two  parts  grain  alcohol  and  one 
part  water.) 

Determination  of  Free  Picric  Acid. 

The  free  picric  acid  present  is  determined  by  the  following 
procedure : 

1 200 

From  a  burette  draw  —=^-  cubic  centimeters  of  the  ben- 
zol solution  into*  a  100  cubic  centimeter  flask  and  evaporate 
to  dryness  to  remove  the  benzol,  proceeding  carefully  accord- 
ing to  the  following  directions.  The  flask  is  placed  in  a  hot 
water  bath  and  a  current  of  air  passed  over  (not  in)  the 
benzol  solution,  at  no  time  allowing  the  level  of  the  hot  water 
to  be  above  the  level  of  the  benzol  solution.  The  flask  should 
be  gently  shaken  during  the  evaporation  to  keep  the  walls 
moistened  and  to  avoid  overheating  any  part.  (4)  Keep  the 
flask  about  I  minute  in  the  hot  water  after  the  residue  ap- 
pears dry,  then  remove,  but  continue  the  air  current  until  the 
odor  of  benzol  can  no  longer  be  detected. 

Dissolve  the  residue  in  the  flask  with  10  cubic  centimeters 
of  95  per  cent,  alcohol,  heating  gently  if  necessary,  then  pre- 
cipitate the  naphthalene-picrate  by  adding  distilled  water 
slowly,  with  agitation,  until  the  volume  is  exactly  100  cubic 
centimeters.  The  temperature  of  this  solution  must  be  cooled 
to  20°  C. — in  no  case  more  than  2°  higher  or  lower. 

Filter  through  a  dry  filter  into  a  100  cubic  centimeter  cyl- 
inder and  titrate  90  cubic  centimeters  of  the  filtrate  with  N/5 
NaOH  using  methyl  red  as  indicator.  The  cubic  centimeters 
N/5  NaOH  taken  divided  by  0.9  give  the  titre  required  for 

the  free  picric  acid  in  — =-    cubic  centimeters  of  the  original 
benzol  solution. 

If  F  =  cc.  N/5  NaOH  required  for  this  ^?  cc. 

250 

Then  F  X  1200  =  NaOH    required    for  the  free  picric 
T         acid  in  the  whole  benzol  solution. 


Calculation  of  the  Naphthalene  from  the  Picric  Acid  Titres. 

The  difference  between  the  total  titre  and  the  free  acid  titre 
is  the  titre  of  the  picric  acid  combined  as  naphthalene-picrate, 
and  this  latter  titre,  multiplied  by  its  naphthalene  equivalent, 
gives  the  grams  naphthalene  in  the  gas  sample  taken,  as  fol- 
lows: 

Grams  naphthalene 
Free  acid  equivalent  to  i  cc. 

Total  titre  titre  N/s  NaOH 


I  5  T  --  (F  X  1200)     X      0.0256  —  Grams  n  aphthalene  in 
T  gas  sample. 

or,  simplified  o.oo53T  (24  —  F)  =  grams  naphthalene  in  gas 

sample,  and  -  —  —  grams  naphthalene  per  cu. 

cu.   ft.   gas  taken 

ft.  gas.     which  X  15.43  —  grains  per  cu.  ft. 
Notes  on  the  Method, 

1 I )  The  reactions  involved  in  the  method  are  the  following : 
Naphthalene  Picric  acid  Naphthalene  picrate 

C10H8         f  C6H2(N02)3OH  =  C6H2(N02)3OH.C10H8+H20 

Picric  acid  Sodium  picrate 

C6H2(N02)3OH  "  =  C  H  (NO)  ONa  H 

C6H2(N02)3OH.C10H8  +  NaOH  = 

C6Ha(N02)3ONa  +  C10H8  +  H2O. 

(2)  To  absorb  the  naphthalene  completely  the  picric  acid 
solution  must  be  fully  saturated,  and  to  insure  this  an  excess 
of  crystals  must  be  present. 


(3)  The  reason  for  taking  cubic  centimeters  of  the 

benzol  solution  for  the  free  picric  acid  test  is  that  this  is  the 
quantity  which  contains  the  right  amount  of  total  picric  acid 
(i.i  grams)  to  saturate  the  100  cubic  centimeters  of  solution 
to  which  it  is  finally  made  up,  and  this  saturation  is  essential 
to  prevent  decomposition  of  the  naphthalene  picrate  present 
at  the  stated  temperature  (20°  C.). 


176 

(4)  Naphthalene  picrate  is  easily  decomposed  by  heat, 
evolving  naphthalene  and  leaving  behind  free  picric  acid. 

Reagents— N/5  NaOH. 

Saturated  picric  acid  solution  of  known  strength  (100  cubic 
centimeters  picric  acid  should  be  equivalent  to  28-35  cubic 
centimeters  N/5  NaOH). 

Methyl  red  or  lacmoid  indicator. 

Standardising,  of  the  Picric  Acid. 

Filter  500  cubic  centimeters  of  strongly  saturated  picric  acid 
solution.  Take  100  cubic  centimeters  of  filtrate  and  titrate 
against  N/5  NaOH,  using  methyl  red  or  lacmoid  indicator. 
Between  28  and  35  cubic  centimeters  N/5  NaOH  should  be 
required.  Let  titre  equal  "A." 

Test. 

Wash  15  to  50  cubic  feet  of  gas  through  the  remaining  400 
cubic  centimeters  of  picric  acid.  The  gas  should  first  pass 
through  a  dilute  H2,SO4  solution,  next  an  empty  bottle  and  then 
through  at  least  two  picric  acid  wash  bottles.  The  gas  should 
be  washed  at  the  rate  of  i  or  2  cubic  feet  per  hour. 

As  rubber  absorbs  naphthalene  the  connections  between 
bottles,  and  to  the  supply  pipe,  must  be  so  made  that  little  or 
no  rubber  is  exposed  to  the  gas.  (Glass  to  glass.) 

Determination. 

Mix  the  picric  acid  solution  and  filter.  Reject  the  first  50 
cubic  centimeters.  Take  the  next  100  cubic  centimeters  and 
titrate  against  N/5  NaOH.  Let  titre  equal  B.  Let  C  equal 
the  N/5  NaOH  equivalent  of  naphthalene  in  one- fourth  of 
gas  used.  Then  A  —  B  =  C. 

One  cubic  centimeter  N/5  NaOH  equals  0.0256  gram  naph- 
thalene. 

Therefore :  4  x  c  x  0.0256  equals  grams  naphthalene  in  gas 
tested. 


177 

For  Example. 

In  a  test,  69  cubic  feet  of  gas  were  washed.  Titre  A  re- 
quired 31.8  cubic  centimeters  N/5  NaOH.  Titre  B  required 
30.4  cubic  centimeters  N/5  NaOH. 

31.8  —  30.4  equals  1.4. 

4  x  1.4  x  0.0256  equals  0.14336  grams  naphthalene. 
0.14336  divided  by  69  equals  0.00208  grams  C10H8  per  cubic 
foot  gas  used. 

Remarks. 

Grams  naphthalene  per  cubic  foot  x  1543  =  grains  naph- 
thalene per  loo  cubic  feet. 

(O    ^     T  cS 
p 7 — - —    -  grains  naphthalene  per  100  cu.  ft.) 

A  picric  acid  solution  containing  12  grams  per  liter  picric 
acid  is  saturated  at  15°  C.  though  it  can  be  colled  several 
degrees  lower  without  separation  of  picric  acid.  If  the  latter 
separation  takes  place  during  the  test  a  serious  error  may  re- 
sult, consequently  the  solution  must  not  be  too  strong  for  the 
temperature  to  which  it  may  be  exposed  and  a  12  grams  per 
liter  solution  is  recommended  for  ordinary  temperature  (15° 
to  25°  C.). 

Since  the  naphthalene  content  is  calculated  from  a  small 
difference  between  two  large  titres  the  latter  must  be  carefully 
and  exactly  performed.  The  best  indicator  appears  to  be 
methyl  red. 

DETERMINATION  OF  CYANIDE  IN  GAS. 

In  each  of  a  series  of  three  Muencke  gas  washing  bottles 
are  placed  20  cubic  centimeters  of  a  strong  solution  of  caustic 
soda  (1:3),  to  which  is  added  50  cubic  centimeters  of  sus- 
pended ferrous  hydroxide.  The  ferrous  hydroxide  used  is 
prepared  by  adding  40  cubic  centimeters  of  the  caustic  solu- 
tion to  60  cubic  centimeters  of  a  10  per  cent,  solution  of  fer- 
rous sulphate,  allowing  the  precipitate  of  ferrous  hydroxide 
to  settle,  decanting  off  the  solution  containing  sodium  sulphate, 


and  making  the  volume  of  suspended  ferrous  hydroxide  up  to 
150  cubic  centimeters  with  water.  About  5  cubic  feet  of  gas 
are  passed  for  each  test,  at  the  rate  of  approximately  2.5  cubic 
feet  per  hour.  The  contents  of  the  three  bottles  are  then  trans- 
ferred to  a  flask,  boiled  for  15  minutes,  allowed  to  cool,  and 
filtered.  The  filtrate  is  made  up  to  500  cubic  centimeters  and 
an  aliquot  part  100  cubic  centimeters  acidulated  with  sulphuric 
acid,  an  excess  of  ferric  alum  added  and  the  precipitated 
Prussian  blue  collected  and  washed  until  free  from  sulphates. 
The  precipitate  with  the  filter  is  at  once  placed  in  an  evap- 
orator, water  added,  and  the  contents  heated  nearly  to  boiling, 
the  amount  of  Prussian  Blue  being  then  directly  determined  by 
titrating  with  N/5O  NaOH.  (The  end  point  is  reached  when 
the  last  trace  of  blue  disappears.) 

If  5  cubic  feet  of  gas  is  used  in  the  test  then : 

i  cubic  centimeter  N/NaOH  =  2.3315  pounds  of  K4Fe- 

(CN)..3H,0, 
or,    i  cubic  centimeter  N/NaOH  =  2.8660  pounds  of  Na4Fe- 

(CN)6.I2H2O  per  10,000  cubic  feet  of  gas. 
i  cubic  centimeter  N/5O  NaOH  =  0.04663  pound  of  K4- 

Fe(CN)6.3H20, 

or,    i   cubic  centimeter  N/5O  NaOH  =  0.05732  pounds  of 
Na4Fe(CN)6.i2H2O  per  10,000  cubic  feet  of  gas. 

DETERMINATION  OF  CO2  IN  GAS. 
(See  under  gas  analysis.) 

DETERMINATION  OF  CS2  IN  GAS.1 

The  gas  is  first  passed  through  cotton  to  remove  tar  and 
then  dried  by  passing  it  over  calcium  chloride  and  then  through 
three  wash  bottles  containing  a  strong  solution  of  NaOH  cov- 
ered with  an  ethereal  solution  of  triethylphosphine  until  a  red 
coloration  appears  in  the  third  bottle.  The  gas  should  be 
passed  very  slowly,  not  over  0.5  cubic  foot  an  hour  and  not 
more  than  2  cubic  feet  of  gas  should  be  used.  After  the 

1  This  method  although  not  in  general  use  is  very  promising  and  worthy  of  con- 
sideration for  further  use. 


179 

third  bottle  becomes  red,  the  contents  of  the  three  bottles  are 
transferred  to  a  beaker  and  filtered  through  a  weighed  filter 
paper,  washed  and  dried.  The  weight  of  the  (CBH2)3PCS2 
multiplied  by  0.392  gives  the  weight  of  CS&. 

DETERMINATION  OF  IRON  CARBONY!^ 

Iron  carbonyl  may  be  determined  by  passing  the  gas  through- 
concentrated  nitric  acid  or  bromine  water  and  determining  the 
iron  in  solution  (due  to  the  decomposition  of  the  carbonyl)  by 
first  evaporating  with  the  addition  of  H2SO4  until  white  fumes 
of  acid  are  coming  off,  then  dilute  with  water,  reduce  with 
zinc,  and  titrate  with  standard  permanganate.  This  amount 
of  iron  multiplied  with  3.5  gives  the  weight  of  iron  carbonyl. 
Since  the  carbonyl  is  present  in  very  minute  quantities  large 
volumes  of  gas  (at  least  100  cubic  feet)  have  to  be  treated 
to  obtain  any  tangible  results. 

1  This  method  although  not  in  general  use  is  very  promising  and  worthy  of  con- 
sideration for  further  use. 


CHAPTER  IV. 

TESTS  OF  TAR  PRODUCTS  AND  LIGHT  OILS. 

i.  CRUDE:  GAS  BENZOLS. 

a.  Bulb  Distillation. 

APPARATUS. 


FIG.  39. 


Flask :  The  flask  used  shall  be  the  standard  Engler  flask, 
as  described  in  the  various  standard  works  upon  petroleum, 
such  as  Redwood,  Holde,  etc. 

"Engler  employs  a  globular  flask  6.5  centimeters  in  diam- 


eter,  with  a  cylindrical  neck  1.6  centimeters  in  internal  diameter 
and  15  centimeters  in  length,  from  the  side  of  which  a  vapor 
tube  10  centimeters  in  length  extends  at  an  angle  of  75° 
downwards  to  the  condenser.  The  junction  of  the  vapor  tube 
with  the  neck  of  the  flask  should  be  9  centimeters  above  the 
surface  of  the  oil  when  the  flask  contains  its  charge  of  100 
cubic  centimeters  of  oil.  The  observance  of  the  prescribed 
dimensions  is  considered  essential  to  the  attainment  of  uni- 
formity of  results."  (Redwood,  3rd  Ed.,  Vol.  II,  p.  205,  1913.) 

The  flask  shall  be  supported  in  a  ring  of  asbestos  having  an 
opening  iJ/£  inches  in  diameter  in  its  center. 

The  flask,  burner,  etc.,  shall  be  surrounded  by  a  shield. 

Condenser:  The  condenser  shall  consist  of  a  tube  of  thin 
glass  24  inches  in  length,  set  at  an  angle  of  75°  with  the  flask 
surrounded  by  a  water-jacket  of  the  through  type. 

The  thermometer  shall  conform  to  the  following  require- 
ments : 

The  thermometer  shall  be  made  of  resistance  glass  of  a 
quality  equivalent  to  suitable  grades  of  Jena  or  Corning  makes. 
It  shall  be  thoroughly  annealed.  It  shall  be  filled  above  the 
mercury  with  inert  gas  which  will  not  act  chemically  on  or 
contaminate  the  mercury.  The  pressure  of  the  gas  shall  be 
sufficient  to  prevent  separation  of  the  mercury  column  at  all 
temperatures  of  the  scale.  There  shall  be  a  reservoir  above 
the  final  graduation  large  enough  so  that  the  pressure  will  not 
become  excessive  at  the  highest  temperatures.  The  thermom- 
eter shall  be  finished  at  the  top  with  a  small  glass  ring  or 
button  suitable  for  attaching  a  tag.  Each  thermometer  shall 
have  for  identification  the  makers'  name,  a  serial  number,  and 
the  letters  "A.  S.  T.  M.  DISTILLATION." 

The  thermometer  shall  be  graduated  from  o°  to  400°  C.  at 
intervals  of  i°  C.  Every  fifth  graduation  shall  be  longer  than 
the  intermediate  ones,  and  every  tenth  graduation  beginning  at 
zero  shall  be  numbered.  The  graduation  marks  and  numbers 
shall  be  clear-cut  and  distinct. 

The  thermometer  shall  conform  to  the  following  dimensions  : 


182 


Total  length,  mm 385      maximum 

Diameter  of  stem,  mm 7,    tolerance  0.5 

Diameter  of  bulb,  mm 5     minimum,  and  shall  not 

exceed  that  of  the 
stem 

Length  of  bulb,  mm 12.5,  tolerance    2.5 

Distance  o°  to  bottom  of  bulb 30,    tolerance    5 

Distance  o°-4OO°   295,    tolerance  10 

The  accuracy  of  the  thermometer  when  delivered  to  the 
purchaser  shall  be  such  that  when  tested  at  full  immersion  the 
maximum  error  from  o°-2OO°  C.  shall  not  exceed  0.5° ;  200°- 
300°  C.,  it  shall  not  exceed  i°  C.;  3OO°-375°  C.,  it  shall  not 
exceed  1.5°  C. 

The  sensitiveness  of  the  thermometer  shall  be  such  that 
when  taken  at  a  temperature  of  26°  C.  and  plunged  into  a 
free  flow  of  steam,  the  meniscus  shall  pass  the  90°  C.  mark 
in  not  more  than  six  seconds. 

The  thermometer  shall  be  inserted  through  a  tight-fitting 
cork  in  the  neck  of  the  flask,  so  that  the  top  of  the  thermometer 
bulb  will  be  on  a  level  with  the  bottom  of  the  side  outlet  in  the 
neck  of  the  flask  and  in  the  center  of  the  neck. 

METHOD  OF  DISTILLATION. 

The  flask,  connected  with  the  condenser,  shall  be  filled  with 
100  cubic  centimeters  of  the  material  at  15.5°  C.,  which  shall  be 
measured  in  the  100  cubic  centimeter  receiving  cylinder.  The 
same  cylinder  may  be  used  without  drying  as  the  receiving 
vessel  for  the  distillate.  The  flask  shall  be  heated  directly  by  a 
suitable  burner. 

The  distillation  shall  proceed  at  the  rate  of  not  less  than  4 
nor  more  than  5  cubic  centimeters  per  minute,  into  the  receiv- 
ing cylinder.  The  temperature  at  which  the  first  drop  leaves 
the  lower  end  of  the  condenser  shall  be  considered  the  initial 
boiling-point. 

Readings  of  the  quantity  in  the  receiver  shall  be  taken  when 
the  next  10°  point  is  reached,  and  for  every  even  10°  there- 
after. For  example,  if  initial  boiling-point  occurs  at  104°, 
then  the  first  reading  of  the  quantity  in  the  receiver  shall  be 
made  at  110°,  and  thereafter  at  120°,  130°,  etc. 


The  distillation  shall  be  continued  until  the  point  is  reached 
where  the  last  drop  is  vaporized,  when  a  puff  of  white  vapor 
usually  appears  in  the  bottom  of  the  flask.  The  temperature  at 


100 

10  I 

102 

103 
|o<» 
105 
ioa 

107 


7  \ 


22 


FIG.  40. 

this  point  shall  be  considered  the  end  or  dry  point  of  distilla- 
tion. 

The  total  yield  of  distillate  shall  not  be  less  than  97  per  cent. 


184 


(This  method  is  adapted  with  some  modification  from  re- 
port of  Sub-Committee,  D—  i,  A.  $.  T.  M.,  1915). 

b.  Specific  Gravity. 

i..  Hydrometer:  The  hydrometer  shall  be  of  the  form  and 
dimensions  shown  in  Fig.  40.  The  cylinder  shall  be  of  the 
form  and  dimensions  shown  in  Fig.  41.  A  set  of  three  with 


FIG.  41. 

ranges  of  0.79  to  0.87,  0.86  to  0.94,  and  0.93  to  i.oi,  will 
suffice.  The  readings  should  be  preferably  taken  at  15.5°  C. 
Before  taking  the  specific  gravity,  the  oil  in  the  cylinder  should 
be  thoroughly  stirred.  Care  should  be  taken  that  the  hydrom- 
eter does  not  touch  the  sides  or  bottom  of  the  cylinder  when 
the  reading -is  taken,  and  that  the  oil  surface  is  free  from  froth 
and  bubbles.  If  the  specific  gravity  is  determined  at  a  higher 


temperature  than  15.5°  C.,  correction  should  be  made  by  add- 
ing o.ooi  for  each  degree  Centigrade  excess  of  temperature. 
(This  correction  figure  is  only  an  approximate  one,  and  should 
not  be  used  when  exact  work  is  desired.) 
'  2.  Westphal  Balance — Reference  Method:  The  balance 
should  be  set  up  and  adjusted  so  that  the  plummet  when  sus- 
pended to  swing  freely  in  air,  exactly  balances  the  beam.  A 
reading  is  then  taken  with  the  plummet  immersed  in  water  at 
15.5°  C.,  and  if  the  balance  is  properly  made  and  adjusted, 
this  should  be  i.oo.  A  second  reading  in  oil  at  15.5°  C.  gives 
the  specific  gravity  directly.  If  for  any  reason  the  water 
reading  is  not  i.oo,  the  balance  should  not  be  adjusted  in 
water,  but  the  oil  reading  divided  by  the  water  reading  should 
be  taken  as  the  specific  gravity. 

c.  Wash  with  Acid,  Followed  by  Steam  Distillation 
for  Valuation  of  Crudes. 

Three  hundred  cubic  centimeters  of  the  material  to  be  tested 
are  measured  from  a  cylinder  into  a  500  cubic  centimeter 
Squibb  type  separatory  funnel.  About  4  cubic  centimeters  of 
66°  Baume  sulphuric  acid  is  added,  and  the  contents  of  the 
funnel  thoroughly  shaken,  care  being  taken  to  avoid  piling 
up  of  pressure  in  the  funnel,  due  to  heat  of  reaction.  After 
settling  for  15  minutes,  the  lower  layer  of  acid  is  drawn  off 
and  a  second  wash  of  17  cubic  centimeters  of  acid  is  applied, 
and  likewise  removed.  (The  total  amount  of  acid  used  is  ap- 
proximately equivalent  to  one  pound  per  gallen  of  material.) 
The  last  acid  wash  is  followed  by  a  treatment  with  10  per  cent, 
caustic  soda  solution  to  alkaline  reaction.  This  soda  is  al- 
lowed to  settle  and  is  drawn  off. 

The  treated  benzol  is  run  into  a  500  cubic  centimeter  short- 
neck  bulb  and  distilled  in  a  current  of  steam  until  no  more  oil 
is  visible  in  the  distillate.  The  flask  containing  the  treated 
benzol  should  be  kept  warm  enough  by  a  burner  during  the 
course  of  the  distillation  to  prevent  undue  condensation  of 
steam.  The  volume  of  oil  distillate  is  measured,  and  divided 


i86 

by  three,  gives  the  percentage  of  refined  benzols  in  the  crude 
gas  benzol. 

(Steam  distillation  is  necessary  here  to  avoid  possible  de- 
composition. A  redistillation  by  method  i-a  may  be  made  if 
there  is  any  indication  of  the  presence  of  wash  oil  in  the  dis- 
tillate.) 

2.  HOLDER  OILS  (DRIP  OILS). 

a.  Bulb  Distillation. 

Same  as  i-a,  with  the  exception  that  the  distillation  is  not 
continued  to  the  drying  point,  but  only  to  the  point  where  95 
per  cent,  of  the  material  is  distilled  off. 

b.  Specific  Gravity. 

Same  as  i-b.  If  the  specific  gravity  is  determined  at  a 
higher  temperature  than  15.5°  C.,  correction  should  be  made 
by  adding  0.00088  for  each  degree  Centigrade  excess  of  tem- 
perature. 

c.  Distillation  with  Dephlegmator. 

One  hundred  cubic  centimeters  of  the  oil  are  placed  in  a  flask 
equipped  with  Hempel  distilling  tube,  supplied  with  solid  glass 
beads  of  4.8  to  5.5  millimeters  diameter  to  a  depth  of  75  milli- 
meters, and  distilled,  noting  the  cubic  centimeters  distillate  at 
170°  C.  and  200°  C.  The  first  fraction  represents  approxi- 
mately crude  benzol,  toluol  and  solvent,  and  the  170-200°  frac- 
tion heavy  naphtha. 

NOTE. — A  6-ftulb  Lebel  column  or  12-bulb  Young  pearhead 
flask  may  be  substituted  for  the  Hempel  tube  in  this  test. 

d.    Naphthalene. 

The  residue  above  200°  left  in  the  flask  (c)  is  transferred 
to  a  copper  beaker  and  cooled  to  15.5°  C.  for  15  minutes. 
The  mass  is  filtered  on  a  perforated  funnel  in  a  suction  pump 
and  sucked  dry.  The  naphthalene  in  the  filter  is  then  pressed 
between  paper  in  a  letter  press  to  remove  all  oil,  and  weighed. 

This  test  is  not  very  accurate. 


i87 

3.  BENZOLS  AND  REFINED  NAPHTHAS. 

a.  Bulb  Distillation. 

Same  as  i-a,  with  the  exception  of  tests  on  pure  benzol  and 
pure  toluol.  With  these  materials,  readings  of  the  per  cent. 
distilled  are  taken  every  0.2°  C.  and  a  thermometer  of  the 
following  specifications  may  be  used: 

Dimensions: — 

Total  length,  mm. 370 — 400 

Diameter,  mm.  6.5—7.5 

Bulb  length,  mm.  (max.) 10 

Bulb  diameter,  mm. 4-5—5-5 

Scale. — Scale  to  start  not  less  than  75  millimeters  above 
bottom  of  bulb,  and  to  be  from  240  to  270  millimeters  long. 

General. — The  thermometer  shall  be  furnished  with  an  ex- 
pansion chamber  at  the  top  and  have  a  ring  for  attaching  tags. 

Range. — 60°  to  140°  C.,  in  fifths  of  a  degree. 

Accuracy. — To  be  correct  to  one-fifth  degree  Centigrade. 

b.  Specific  Gravity. 
Same  as  i-b. 

c.  Sulphuric  Acid  Wash  Test. 

ACID  WASHING  TEST   FOR  BENZOL,  TOLUOL,   SOLVENT 
NAPHTHA,  ETC. 

Semet-Solvay  Company's  Modification  of  The  Barrett  Company's 

Method.    Adopted  by  The  Barrett  Company  on  July  I,  1916. 

(Revised.) 

The  set  of  color  standards  consists  of  15  bottles  (French 
squares,  stoppered,  I  ounce  capacity),  each  containing  one  of 
the  colored  solutions  made  up  as  given  below  and  the  bottle 
sealed. 

When  making  a  test  for  amount  of  acid  washing  a  simi- 
lar bottle  is  used.  Seven  cubic  centimeters  of  96  per  cent.  C. 
P.  sulphuric  acid  is  put  in  first,  and  then  approximately  21 
cubic  centimeters  of  the  material  to  be  tested  is  added;  shake 
thoroughly  for  15  to  20  seconds  and  allow  to  stand  for  the 
specified  time;  compare  the  resulting  color  of  the  acid  layer 


i88 

with  the  standard  set  and  determine  which  number  it  corre- 
sponds to. 

In  pure  benzol  and  pure  toluol  testing  the  benzol  or  toluol 
layer  must  remain  white,  and  the  color  of  the  acid  layer  after 
standing  15  minutes,  but  not  be  darker  than  No.  4. 

For  90  per  cent,  benzol  and  all  grades  of  benzol  and  toluol 
other  than  pure,  the  benzol  and  toluol  layer  must  remain  white, 
and  the  color  of  the  acid  layer  after  standing  15  minutes  must 
not  be  darker  than  No.  6. 

For  xylol,  the  xylol  layer  must  remain  white  and  the  color 
of  the  acid  layer  after  standing  15  minutes  must  not  be  darker 
than  No.  6. 

For  solvent  naphtha  the  acid  layer  color  only  is  noted,  and 
after  5  minutes  standing  it  must  not  be  darker  than  No.  14. 

It  is  well  to  note  that  the  above  schedule  shows  the  limit  of 
color  allowable  in  the  sales  specifications;  and  it  is  to  be  ex- 
pected that  to  consistently  pass  the  test,  works  practice  should 
call  for  a  limit  of  at  least  one  number  lighter  in  each  case. 

The  solutions  for  the  standards  are  made  up  as  follows : 

The  following  basic  solutions  are  used: 

A.  59.4965  grams  CoCl2.6H2O  (nickel  free)  is  made  up  to 

1,000  cubic  centimeters  with  a  mixture  of  25  cubic 
centimeters  31  per  cent.  HC1  and  975  cubic  centi- 
meters H2O. 

B.  45.054  grams  FeCl3.6H,2O  made  up  to  1,000  cubic  centi- 

meters with  a  mixture  of  25  cubic  centimeters  31  per 
cent.  HC1  and  975  cubic  centimeters  H2O. 

C.  3.5  volumes  of  solution  A  -f-  36.5  volumes  solution  B  -)- 

90  volumes  of  H2O. 

D.  3.5  volumes  of  solution  A  +  36.5  volumes  of  solution  B 

(No  water  is  added.) 

E.  Solution  of  K2CrO4  saturated  at  21°  C. 

F.  One  volume  of  a  solution  of  K2Cr2O7  saturated  at  21°  C. 

+  i  volume  of  H2O. 

As  standard  color  solutions  to  be  used  for  comparison  the 
following  are  made  up  and  numbered  from  o  to  14 : 


rig 

No.     o. — Pure  water. 

No.     i. — i  volume  of  solution  C  +  i  volume  of  H2O. 

No.     2.. — 5^  volumes  of  solution  C  +  2  volumes  of  H2O. 

No.     3. — Solution  C  as  such. 

No.     4. — i  volume  of  solution  D  -|-  i  volume  of  H2O. 

No.     5. — 5^2  volumes  of  solution  D  -j-  2  volumes  of  H2O. 

No.     6. — Solution  D  as  such. 

No.     7. — 5  volumes  of  solution  E  +  2  volumes  of  water. 

No.     8. — Solution  E  as  such. 

No.  9. — 7  volumes  of  solution  E  +  J^  volume  of  solution 
F. 

No.  10. — 6^  volumes  of  solution  E  -j-  i  volume  of  solu- 
tion F. 

No.  ii. — 5^2  volumes  of  solution  E  +  2  volumes  of  solu- 
tion F. 

No.  12. — i  volume  of  solution  E  +  i  volume  of  solution  F. 

No.  13. — 2  volumes  of  solution  E  +  5  volumes  of  solution 
F. 

No.  14. — Solution  F  as  such. 

(These  standard  solutions  should,  in  all  cases,  remain  stop- 
pered to  prevent  evaporation.) 

To  make  the  test  place  approximately  7  cubic  centimeters 
of  C.  P.  sulphuric  acid  and  21  cubic  centimeters  of  the  light 
oil  to  be  tested  in  one  of  these  standard  bottles,  shake  thor- 
oughly and  stand  aside  for  15  minutes  (in  all  cases  excepting 
the  test  for  solvent  naphtha,  in  which  5  minutes  is  the  limit.) 
At  the  end  of  15  minutes  compare  the  color  produced  in  the 
sample  with  that  of  the  standard  solution  by  looking  through 
the  tube  towards  the  light. 

In  making  up  the  standard  color  comparison  solutions,  put 
in  an  amount  of  colored  solution  equivalent  to  the  amount  of 
acid  used  in  the  test,  and  on  top  of  it  put  the  amount  of  benzol 
used  in  the  test.  This  gives  an  apparent  exact  duplicate  of  a 
wash  test.  In  all  cases,  except  solvent  naphtha,  the  light  oil 
should  remain  white,  the  color  test  being  applied  only  to  the 
color  of  the  acid.  In  the  case  of  solvent  naphtha  no  specifica- 
tion is  made  as  to  the  color  of  the  solvent  naphtha  itself,  since 
13 


190 

it  will  not  be  white,  but  the  color  of  the  acid  compared  with 
this  standard  color  solution  determines  the  degree  of  washing. 
For  pure  benzol  and  toluol,  standard  sample  No.  4  has  been 
adopted  as  the  greatest  amount  of  color  allowable  for  these 
grades.  For  all  commercial  grades,  such  as  90  per  cent,  ben- 
zol, 50  per  cent,  benzol  and  commercial  toluol,  No.  6  is  the 
lowest  color  limit.  For  solvent  naphtha  No.  14  has  been 
adopted. 

d.  Solidifying  Point  (for  pure  benzol  only). 

Fifty  cubic  centimeters  are  taken  in  a  test  tube  with  the 
thermometer  in  the  liquid,  and  cooled  with  stirring  until  sep- 
aration of  crystals  occurs.  At  this  point  there  is  a  constant 
temperature  for  a  considerable  period,  which  is  taken  as  the 
solidifying  point.  If  the  material  supercools,  the  temperature 
rises  as  the  crystals  separate,  and  the  highest  point  reached  is 
taken  as  the  solidifying  point. 

e.  Unnitrifiable  Hydrocarbons. 

Place  100  cubic  centimeters  of  material  in  a  flask  of  about 
500  cubic  centimeters  capacity,  provided  with  a  dropping  fun- 
nel and  a  long  tube  (drawing)  for  condensing  any  hydrocar- 
bon volatilizing.  Prepare  a  mixture  of  150  grams  nitric  acid 
of  specific  gravity  1.4,  and  180  or  200  grams  sulphuric  acid, 
specific  gravity  1.84,  which  must  be  allowed  to  cool  before  use. 
Run  this,  drop  by  drop,  through  the  tap- funnel  into  the  ben- 
zol, shaking  this  up  almost  constantly.  As  soon  as  the  tem- 
perature rises,  cool  the  flask  by  immersing  it  in  a  dish  full  of 
water.  When  all  the  acid  has  been  added,  and  when  no  further 
rise  of  temperature  takes  place  spontaneously,  heat  the  flask 
gently  for  an  hour  or  two  (during  this  time  the  tube  is  best 
replaced  by  a  proper  reflux  condenser).  Allow  the  whole  to 
settle,  and  separate  the  lower  acid  layer  by  means  of  a  separa- 
ting funnel  from  the  crude  nitrobenzol.  Dilute  the  acid  with 
several  times  its  bulk  of  water ;  any  oily  liquid  separating  after 
a  few  hours'  rest  is  added  to  the  nitrobenzol.  Wash  the 
crude  nitrobenzol  three  times  with  its  own  bulk  of  water, 


191 

once  with  a  very  dilute  solution  of  caustic  soda  (if  this  so- 
lution is  employed  too  concentrated,  an  emulsion  is  formed 
which  is  very  awkward  to  manage),  and  again  with  water, 
taking  care  that  no  oil  is  lost  in  separating  the  washings. 
The  well-settled  liquor  can  be  at  once  tested  for  its  specific 
gravity,  which  in  the  case  of  90  per  cent,  benzol  ought 
to  be  1.20;  with  50  per  cent,  benzol  1.19  at  15°;  but  this 
is  not  decisive,  as  the  nitrobenzol  is  not  quite  free  from  water, 
and  some  benzol  may  have  escaped  nitrification.  The  liquor 
is  therefore  distilled  from  a  fractionating  flask  till  the  tem- 
perature has  reached  150°,  and  the  distillate  is  once  more 
nitrated,  but  this  time  with  large  excess  of  the  acid  mixture; 
anything  remaining  undissolved  may  be  regarded  as  unnitrifi- 
able  hydrocarbons.  Theoretically,  100  parts  of  benzol  furnish 
157.6  of  nitrobenzol;  100  parts  of  toluol,  148.9  of  nitrotoluol. 
(Taken  from  Lunge's  Coal  Tar  and  Ammonia.) 

NOTE:— This  method  is  not  accurate  with  material  containing  small  quantities 
of  paramne. 

4.  TAR. 
a.  Water. 
Measure  50  cubic  centimeters  of  coal  tar  naphtha  or  light 


FIG.  42. 

oil   (which  must  be  tested  to  determine  that  it  is  free  from 


1 92 


193 

water,  whenever  a  new  supply  is  required)  in  a  250  cubic 
centimeter  measuring  cylinder.  (No  objection  is  raised  to 
measuring  the  tar  direct  into  the  still  or  in  other  ways,  but 
the  measurement  must  be  made  as  described  in  case  of  dis- 
pute.) Add  200  cubic  centimeters  of  the  tar.  Transfer  con- 
tents of  cylinder  to  copper  still  and  wash  the  cylinder  with 
50-75  cubic  centimeters  more  of  naphtha,  adding  the  washings 
to  contents  of  the  still.  Attach  lid  and  clamp,  using  a  paper 
gasket  and  set  up  apparatus  (Fig.  No.  42).  Apply  heat  by 
means  of  the  ring  burner  and  distil  until  the  vapor  temper- 
ature, as  indicated  by  the  thermometer  (in  this  and  all  other 
tests  care  must  be  used  to  have  the  thermometer  set  exactly 
as  shown  in  drawing)  has  reached  205°  C.  The  distillate  is 
collected  in  the  separatory  funnel,  to  which  15-20  cubic  centi- 
meters of  benzol  have  been  previously  added.  This  effects  a 
clean  separation  of  the  water  and  oil.  The  reading  is  made 
after  twirling  the  funnel  and  allowing  to  settle  for  a  few  min- 
utes. The  percentage  is  figured  by  volume. 

NOTE. — In  case  a  large  percentage  of  water  is  present,  a 
vacuum  head  as  shown  in  Fig.  32,  Chap.  II,  "Tar,"  may  be 
used  to  advantage. 

b.  Distillation. 

Apparatus. — The  apparatus  shall  consist  of  the  following 
standard  parts: 

(a)  Flask. — The  distillation  flask  shall  be  a  250  cubic  centi- 
meter Engler  distilling  flask,  having  the  following  dimensions : 

Diameter  of  bulb,  cm. 8.0 

Length  of  neck,  cm.  15.0 

Diameter  of  neck,  cm. 1.7 

Surface  of  material  to  lower  side  of  tubulature,  cm n.o 

Length  of  tubulature,  cm 15.0 

Diameter  of  tubulature,  cm. 0.9 

Angle  of  tubultaure 75° 

A  variation  of  3  per  cent,  from  the  above  measurements  will 
be  allowed. 

The  thermometer  shall  conform  to  the  following  require- 
ments : 

The  thermometer  shall  be  made  of  resistance  glass  of  a 
quality  equivalent  to  suitable  grades  of  Jena  or  Corning  makes. 


194 

It  shall  be  thoroughly  annealed.  It  shall  be  filled  above  the 
mercury  with  inert  gas  which  will  not  act  chemically  on  or 
contaminate  the  mercury.  The  pressure  of  the  gas  shall  be 
sufficient  to  prevent  separation  of  the  mercury  column  at  all 
temperatures  of  the  scale.  There  shall  be  a  reservoir  above 
the  final  graduation  large  enough  so  that  the  pressure  will  not 
become  excessive  at  the  highest  temperatures.  The  thermom- 
eter shall  be  finished  at  the  top  with  a  small  glass  ring  or 
button  suitable  for  attaching  a  tag.  Each  thermometer  shall 
have  for  identification  the  makers'  name,  a  serial  number,  and 
the  letters  "A.  S.  T.  M.  DISTILLATION." 

The  thermometer  shall  be  graduated  from  o°  to  400°  C.  at 
intervals  of  i°  C.  Every  fifth  graduation  shall  be  longer  than 
the  intermediate  ones,  and  every  tenth  graduation  beginning  at 
zero  shall  be  numbered.  The  graduation  marks  and  numbers 
shall  be  clear-cut  and  distinct. 

The  thermometer  shall  conform  to  the  following  dimensions  : 

Total  length,  mm 385     maximum 

Diameter  of  stem,  mm 7,     tolerance  0.5 

Diameter  of  bulb,  mm 5      minimum,  and  shall  not 

exceed  that  of  the 
stem 

Length  of  bulb,  mm 12.5,  tolerance    2.5 

Distance  o°  to  bottom  of  bulb 30,    tolerance    5 

Distance  o°-4OO°   295,    tolerance  10 

The  accuracy  of  the  thermometer  when  delivered  to  the 
purchaser  shall  be  such  that  when  tested  at  full  immersion  the 
maximum  error  from  o°-2OO°  C.  shall  not  exceed  0.5° ;  200°- 
300°  C.,  it  shall  not  exceed  i°  C. ;  3OO°-375°  C.,  it  shall  not 
exceed  1.5°  C. 

The  sensitiveness  of  the  thermometer  shall  be  such  that 
when  taken  at  a  temperature  of  26°  C.  and  plunged  into  a 
free  flow  of  steam,  the  meniscus  shall  pass  the  90°  C.  mark 
in  not  more  than  six  seconds. 

(c)  Condenser. — The  condenser  tube  shall  have  the  follow- 
ing dimensions: 

Length  of  tube,  mm 500 

Width  of  tube,  mm. 12  to  15 

Width  of  adaptor  end  of  tube,  mm .    20  to  25 


195 


(d)  Stands. — Two  iron  stands  shall  be  provided,  one  with 
a  universal  clamp  for  holding  the  condenser,  and  one  with  a 
light  grip  arm  with  a  cork-lined  clamp  for  holding  the  flask. 

(e)  Burner  and  Shield. — A  Bunsen  burner  shall  be  provided 
with  a  tin  shield  20  centimeters  long  by  9  centimeters  in  diam- 
eter.    The  shield  shall  have  a  small  hole  for  observing  the 
flame. 

(/)  Cylinders. — The  cylinders  used  in  collecting  the  distil- 
late shall  have  a  capacity  of  25  cubic  centimeters  and  shall  be 
graduated  in  tenths  of  a  cubic  centimeter. 

Setting  up  the  Apparatus. — The  apparatus  shall  be  set  up  as 


Fig.  44.— Apparatus  for  the  distillation  of  tar. 


196 

shown  in  Fig.  44,  the  thermometer  being  placed  so  that  the 
top  of  the  bulb  is  opposite  the  middle  of  the  tubulature.  All 
connections  should  be  tight. 

Method. — One  hundred  cubic  centimeters  of  the  dehydrated 
material  to  be  tested  shall  be  placed  in  a  tared  flask  and 
weighed.  After  adjusting  the  thermometer,  shield,  condenser, 
etc.,  the  distillation  is  commenced,  the  rate  being  so  regulated 
that  I  cubic  centimeter  passes  over  every  minute.  The  re- 
ceiver is  changed  as  the  mercury  column  passes  the  fraction- 
ating point. 

The  following  fractions  should  be  reported : 

Start  of  distillation  to  no°C. 

iro°C.  to  iyo°C. 

iyo°C.  to  235°C. 

235°C.  to  2yo°C. 

27o°C.  to  3i5°C. 

3i5°C.  to  355°C. 

Residue 

To  determine  the  amount  of  residue,  the  flask  is  weighed 
again  when  distillation  is  complete.  During  the  distillation  the 
condenser  tube  shall  be  warmed  when  necessary  to  prevent 
the  deposition  of  any  sublimate.  The  percentages  of  fractions 
should  be  reported  both  by  weight  and  by  volume. 

(This  method  is  adapted  with  some  modification  from  re- 
port of  Subcommittee  on  Distillation,  Committee  D-4,  A.  S. 
T.  M.,  1911.) 

c.  Specific  Gravity. 

1.  Hydrometer. — Same  as  i-b.    A  set  of  three  with  ranges 
of  1.07  to  1.15,  1.14  to  1.22,  and  1.21  to  1.30  will  suffice.    The 
hydrometer  can  only  be  used  on  tars  for  rough  work,  and  is 
used  at  any  convenient  temperature.     If  the  specific  gravity  is 
determined  at  a  higher  temperature  than  15.5°  C.,  correction 
should  be  made  by  adding  0.000685  for  each  degree  Centigrade 
excess  of  temperature. 

2.  Modified  Hubbard  Bottle. — For  accurate  work  with  the 
bottle^  the  test  should  be  made  on  dry  tar  only.    The  type  of 


197     . 

bottle  used  is  shown  in  Fig.  45.     The  following  weights  are 
noted : 

a.  Weight  of  empty  bottle. 

b.  Weight  of  bottle  filled  with  water  to  the  mark  of 

15.5°  c. 

c.  Weight  of  bottle  partly  filled  with  tar. 

d.  Weight  of  bottle  with  tar  and  water  adjusted  to  the 

mark  at  15.5°  C. 

c  —  a 
The  specific  gravity  then  is  7-7—  ,      . 

(^ 0 d)   \u — C) 


FIG.  45. 


.  —  Freshly  distilled  water  should  be  used  in  this  work. 


d.  Free  Carbon. 

APPARATUS. 
Extractor.  —  The  extraction  apparatus  is  shown  in  Fig.  46. 


FIG.  46. 


198 

Filter  Cups. — The  filter  cups  or  thimbles  are  made  of 
Schleicher  and  Schull  No.  575  hardened  filter  paper,  which 
comes  in  cut  circles.  The  size  used  is  15  centimeters  in  diam- 
eter. To  make  a  cup,  two  circles  should  be  taken  and  one  cut 
down  to  a  diameter  of  about  14  centimeters.  A  round  stick 
about  i  inch  in  diameter  is  used  as  a  form.  The  stick  is  placed 
in  the  center  of  the  circles  of  filter  paper,  the  smaller  inside; 
the  papers  are  then  folded  symmetrically  around  the  stick  to 
form  a  cup  of  about  2j/2  inches  in  length.  A  very  little  prac- 
tice enables  the  operator  to  make  these  evenly  and  quickly. 
After  being  made,  they  are  soaked  in  benzol  to  remove  any 
grease  due  to  handling,  drained,  dried  in  a  steam  oven  and 
kept  in  a  desiccator  until  used. 

Method. — If  tar  is  to  be  assayed,  it  must  be  dried  before 
testing,  and  after  drying  it  is  passed  hot  through  a  3O-mesh 
sieve  to  remove  foreign  substances. 

For  materials  of  5  per  cent,  or  more  carbon  content,  5  grams 
should  be  taken  for  the  test.  With  lesser  percentages,  10 
grams  should  be  used.  The  amount  is  weighed  out  in  a  100 
cubic  centimeter  beaker,  and  digested  with  about  50  cubic  cen- 
timeters of  chemically  pure  toluol  on  the  steam  bath  for  a 
period  not  to  exceed  30  minutes.  If  the  solution  is  kept  hot 
and  constantly  stirred,  the  digestion  can  be  completed  very 
rapidly.  A  filter  cup,  prepared  as  described,  is  weighed  in  a 
weighing  bottle  and  placed  in  a  carbon  filter  tube  over  a  beaker 
or  flask.  The  toluol-tar  mixture  is  now  decanted  through  the 
thimble  and  washed  with  hot  chemically  pure  toluol  until 
clean,  using  some  form  of  policeman  which  is  unaffected  by 
toluol  for  the  purpose  of  detaching  any  carbon  which  may  ad- 
here to  the  beaker.  The  cup  is  finally  given  a  washing  with 
hot  chemically  pure  benzol  and  then,  after  draining  is  cov- 
ered with  a  cap  of  filter  paper  or  alundum,  and  placed  in  the 
extracting  apparatus  in  which  chemically  pure  benzol  is  used 
as  a  solvent.  The  extraction  is  continued  until  the  descend- 
ing benzol  is  colorless.  The  thimble  is  then  removed,  the  cap 
taken  off,  dried  in  the  steam  oven,  and  weighed  in  the  weighing 
bottle  after  cooling  in  the  desiccator.  The  balance  used  for 


199 

this  work  should  be  accurate  to  at  least  a  half  milligram. 

NOTE). — If  desired,  carbon  bisulphide  may  be  used  instead  of 
benzol  and  toluol  as  a  solvent,  but  the  results  may  not  be  com- 
parable. 

5.  TAR  L,IGHT  OILS. 

a.  Bulb  Distillation. 
Same  as  2-a. 

b.  Tar  Acids. 

The  distillate  from  (a)  is  placed  in  a  separatory  funnel 
(Fig.  47).  If  the  light  oil  is  not  liquid  at  room  temperature, 


FIG.  47. 

it  should  be  kept  in  a  constant  temperature  bath  at  a  point 
high  enough  to  insure  all  solid  matter  remaining  in  solution. 
After  the  material  in  the  funnel  has  come  to  constant  tem- 
perature, the  reading  is  noted  and  50  cubic  centimeters  of  a 
10  per  cent,  caustic  soda  solution  added.  It  is  then  shaken  and 
allowed  to  settle,  the  soda  drawn  off,  the  oil  allowed  to  come 
to  its  original  temperature,  and  the  shrinkage  noted.  This 
process  is  repeated  with  successive  portions  of  30  cubic  centi- 
meters each  of  the  same  soda  solution,  until  no  further  shrink- 
age is  noted.  The  total  shrinkage  is  taken  as  the  percentage 
of  tar  acids. 

(This  test  is  empirical,  and  it  would  be  desirable  to  have  a 
more  accurate  method). 

c.  Distillation  with  Dephlegmator. 

Same  as  2-c.     In  this  case  the  extracted  oil  from  the  tar  acid 
determination  is  used  instead  of  the  original. 

d.  Naphthalene. 
Same  as  2-d.     Made  on  residue  above  200°  from  5-^. 

e.  Specific  Gravity. 
Same  as   i-b.     A  set  of  two  hydrometers  with  ranges  of 


200 

0.86  to  0.94,  and  0.93  to  i.oi,  will  suffice.    If  the  specific  grav- 
ity is  determined  at  a  higher  temperature  than  15.5°  C.,  cor- 
rection  should  be  made  by  adding  0.0009   f°r   eacn  degree 
Centigrade  excess  of  temperature. 
Reference  method,  same  as  i-b  (2). 

6.  TAR  MIDDLE  OILS. 

a.  Bulb  Distillation. 
Same  as  2-a. 

b.  Specific  Gravity. 

Same  as  i-b.  A  set  of  two  hydrometers  with  ranges  of  0.93 
to  i.oi,  and  i.oo  to  1.08  will  suffice.  If  the  specific  gravity  is 
determined  at  a  higher  temperature  than  15.5°  C.,  correction 
should  be  made  by  adding  0.00085  for  each  degree  Centigrade 
excess  of  temperature. 

Reference  method,  same  as  i-b  (2). 

c.  Tar  Acids. 
Same  as  5-^. 

d.  Naphthalene. 
Same  as  2-d. 

7.  TAR  HEAVY  OILS  (CREOSOTE  OILS). 

a.  Distillation. 

Retort. — This  shall  be  a  tubulated  Jena  glass  retort  of  the 
usual  form  with  a  capacity  of  250  to  290  cubic  centimeters. 


FIG.  48. 

The  capacity  shall  be  measured  by  placing  the  retort  with  the 


201 


bottom  of  the  bulb  and  the  end  of  the  offtake  in  the  same 
horizontal  plane,  and  pouring  water  into  the  bulb  through  the 
tubulature  until  it  overflows  the  offtake.  The  amount  remain- 
ing in  the  bulb  shall  be  considered  its  capacity.  (See  Fig.  48.) 

Condenser  Tube. — Any  suitable  form  of  glass  tubing  may  be 
used.     (Fig.  49.) 


FIG.  49. 

Shield. — To  be  made  of  asbestos  (Fig.  50)  shall  be  used  to 
protect  the  retort  from  air  currents  and  to  prevent  radiation. 
This  may  be  covered  with  galvanized  iron,  as  such  an  arrange- 
ment is  more  convenient  and  more  permanent. 


-1 


FIG.  50, 

Receivers. — Erlenmeyer  flasks  of  50  to  100  cubic  centi- 
meters capacity  are  most  convenient  forms. 

The  thermometer  shall  conform  to  the  following  require- 
ments : 

The  thermometer  shall  be  made  of  resistance  glass  of  a 
quality  equivalent  to  suitable  grades  of  Jena  or  Corning  makes. 


2O2 

It  shall  be  thoroughly  annealed.  It  shall  be  filled  above  the 
mercury  with  inert  gas  which  will  not  act  chemically  on  or 
contaminate  the  mercury.  The  pressure  of  the  gas  shall  be 
sufficient  to  prevent  separation  of  the  mercury  column  at  all 
temperatures  of  the  scale.  There  shall  be  a  reservoir  above 
the  final  graduation  large  enough  so  that  the  pressure  will  not 
become  excessive  at  the  highest  temperatures.  The  thermom- 
eter shall  be  finished  at  the  top  with  a  small  glass  ring  or 
button  suitable  for  attaching  a  tag.  Each  thermometer  shall 
have  for  identification  the  makers'  name,  a  serial  number,  and 
the  letters  "A.  S.  T.  M.  DISTILLATION." 


FIG.  51. 

The  thermometer  shall  be  graduated  from  o°  to  400°  C.  at 
intervals  of  i°  C.  Every  fifth  graduation  shall  be  longer  than 
the  intermediate  ones,  and  every  tenth  graduation  beginning  at 
zero  shall  be  numbered.  The  graduation  marks  and  numbers 
shall  be  clear-cut  and  distinct. 

The  thermometer  shall  conform  to  the  following  dimensions  : 

Total  length,  mm 385      maximum 

Diameter  of  stem,  mm 7,     tolerance  0.5 

Diameter  of  bulb,  mm 5      minimum,  and  shall  not 

exceed  that  of  the 
stem 

Length  of  bulb,   mm 12.5,  tolerance    2.5 

Distance  o°  to  bottom  of  bulb. . . .     30,    tolerance    5 
Distance  o°-4OO°   295,    tolerance  10 


203 


The  accuracy  of  the  thermometer  when  delivered  to  the 
purchaser  shall  be  such  that  when  tested  at  full  immersion  the 
maximum  error  from  o°-2OO°  C.  shall  not  exceed  0.5° ;  200°- 
300°  C.,  it  shall  not  exceed  i°  C. ;  3OO°-375°  C.,  it  shall  not 
exceed  1.5°  C. 

The  sensitiveness  of  the  thermometer  shall  be  such  that 
when  taken  at  a  temperature  of  26°  C.  and  plunged  into  a 
free  flow  of  steam,  the  meniscus  shall  pass  the  90°  C.  mark 
in  not  more  than  six  seconds. 


FIG.  52. 


Assembling. — The  retort  shall  be  supported  on  a  tripod  of 
rings  over  two  sheets  of  2o-mesh  gauze  6  inches  square.  It 
shall  be  connected  to  the  condenser  tube  by  a  tight  cork  joint. 
The  thermometer  shall  be  inserted  through  a  cork  in  the  tubu- 
lature  with  the  bottom  of  the  bulb  y2  inch  from  the  surface  of 
the  oil  in  the  retort.  The  exact  location  of  the  thermometer 
bulb  shall  be  determined  by  placing  a  vertical  rule  graduated 
in  division  not  exceeding  1/16  inch  back  of  the  retort  when 
the  latter  is  in  position  for  the  test,  and  sighting  the  level  of 


2O4 

the  liquid  and  the  point  for  the  bottom  of  the  thermometer 
bulb.  The  distance  from  the  bulb  of  the  thermometer  to  the 
outlet  end  of  the  condenser  tube  shall  be  not  more  than  24 
nor  more  than  20  inches.  The  burner  should  be  protected 
from  draughts  by  a  suitable  shield  or  chimney. 

Method. — Exactly  100  grams  of  oil  shall  be  weighed  into 
the  retort,  the  apparatus  assembled  and  heat  applied.  The  dis- 
tillation shall  be  conducted  at  the  rate  of  at  least  one  drop  and 
not  more  than  two  drops  per  second,  and  the  distillate  col- 
lected in  weighed  receivers.  The  condenser  tube  shall  be 
warmed  whenever  necessary  to  prevent  accumulation  of  solid 
distillates.  Fractions  shall  be  collected  at  the  following  points  : 

Up  to  i7o°C. 

I7O  tO  2OO°C. 
200  tO  2IO°C. 
210  tO  235°C. 

235  to  27o°C. 
270  to  3i5°C. 
315  to  355°C. 

The  receivers  shall  be  changed  as  the  mercury  passes  the 
dividing  temperature  for  each  fraction.  The  last  receiver  shall 
be  removed  at  355°  C.,  and  the  drainage  from  the  condenser, 
etc.,  shall  not  be  considered  as  a  part  of  the  fraction.  For 
weighing  the  receivers  and  fractions,  a  balance  accurate  to  at 
least  0.05  gram  shall  be  used.  During  the  process  of  distilla- 
tion the  thermometer  shall  remain  in  its  original  position.  No 
correction  shall  be  made  for  the  emergent  stem  of  the  ther- 
mometer. 

When  any  measurable  amount  of  water  is  present  in  the 
distillate,  it  shall  be  separated  as  nearly  as  possible  and  re- 
ported separately,  all  results  being  calculated  on  a  basis  of 
dry  oil.  When  more  than  2  per  cent,  of  water  is  present, 
water-free  oil  shall  be  obtained  by  separately  distilling  a  larger 
quantity  of  oil,  returning  to  the  oil  any  oil  carried  over  within 
the  water,  and  using  dried  oil  for  the  final  distillation.  A 


205 

copper  tar  still  is  a  convenient  means  of  obtaining  water-free 
oil. 

(This  method  is  adapted  with  some  modification  from  report 
of  Sub-Committee  on  Preservatives,  Committee  D-7,  A.  S. 
T.  M.,  1915.) 

Other  methods  for  the  distillation  of  creosote  oil  have  been 
described  by  the  National  Electric  Light  Association,  the  For- 
est Service,  and  Lunge  (Coal  Tar  and  Ammonia). 

b.  Specific  Gravity. 

1.  Same  as  i-b.     A  set  of  two  hydrometers  with  ranges  of 
i.oo  to  i. 08  and  1.07  to  1.15  will  suffice.    If  the  specific  grav- 
ity is  determined  at  a  higher  temperature  than  15.5°  C.,  cor- 
rection should  be  made  by  adding  0.0008  for  each  degree  Cen- 
tigrade excess  of  temperature. 

2.  Westphal  Balance — Reference  Method.    See  i-b  (2).    A 
reading  is  taken  with  the  plummet  immersed  in  water  at  38° 
C.,  and  a  second  reading  in  oil  at  38°  C.    The  specific  gravity 
is  the  oil  reading  divided  by  the  water  reading,  times  0.9939 
(the  density  of  water  at  38°  C.  divided  by  the  density  at  15.5° 
C.). 

c.  Tar  Acids. 

Same  as  5-^.  As  most  creosote  oils  are  not  liquid  at  ordi- 
nary temperatures,  it  is  customary  to  determine  the  tar  acids 
at  a  constant  temperature  of  60°  C. 

8.  PITCH. 
a.  Distillation. 
Same  as  4~b. 

b.  Specific  Gravity. 

Apparatus. — This  consists  entirely  of  a  platinum  pan  having 
a  total  weight  of  about  7  grams. 

Method. — The  pan  is  suspended  above  the  balance  pan  by  a 
fine,  waxed  silk  thread,  and  the  weight  in  air  and  water  at 
15.5°  C.  determined.  It  is  then  filled  with  pitch  and  weighed 
both  in  air  and  in  water  at  15.5°  C. 


2O6 


Formula.  —  Let  a  =  weight  of  pan  in  air. 

b  =  weight  of  pan  in  water. 

c  =  weight  of  pan  plus  pitch  in  air. 

d  =:  weight  of  pan  plus  pitch  in  water. 


The  specific  gravity  ==  (f?         ~^     ^ 
a.  Modified  Hubbard  Bottle.  —  Same  as  4-0. 

c.  Free  Carbon. 

Same  as  4~d.  In  case  the  pitch  is  hard  enough,  it  should  be 
ground  before  making  the  test,  and  the  residue  in  the  extrac- 
tion thimble  should  be  examined  for  extraneous  matter,  such 
as  sticks  of  wood  or  pieces  of  bagging. 

d.  Melting  Point. 

Apparatus  shown  in  Fig.  53. 

1.  Pitches  having  melting-points  from  43°  to  77°  C. 
Pitches  of  this  consistency  can  ordinarily  be  molded  at  room 

temperature,  or  if  necessary,  cold  or  hot  water  can  be  used  to 
harden  or  soften  them.  The  molds  should  always  be  scrupu- 
lously clean,  but  may  be  moistened  if  necessary. 

A  clean-shaped  J/2-inch  cube  of  the  pitch  to  be  formed  in 
the  mold,  placed  on  the  hook  of  No.  12  B.  &  S.  gauge  copper 
wire  (diameter  0.0808  inch),  and  suspended  in  the  600  cubic 
centimeter  beaker,  so  that  the  bottom  of  the  pitch  is  I  inch 
above  the  bottom  of  the  beaker.  (A  sheet  of  paper  placed  on 
the  bottom  of  the  beaker  and  conveniently  weighted  will  pre- 
vent pitch  from  sticking  to  the  beaker  when  it  drops  off.) 
The  pitch  is  to  remain  five  minutes  in  400  cubic  centimeters  of 
freshly  boiled  distilled  water  at  a  temperature  of  15.5°  C.  be- 
fore heat  is  applied;  heat  to  be  applied  in  such  a  manner 
that  the  temperature  of  the  water  is  raised  5°  C.  each  min- 
utes ;  the  temperature  recorded  by  the  thermometer  at  the 
instant  the  pitch  touches  the  bottom  of  beaker  to  be  considered 
the  melting-point. 

2.  Pitches  having  melting-points  below  43°  C. 


207 


Same  method  as  described  in  (i),  except  that  at  the  start 
the  water  should  have  a  temperature  of  4°  C.  The  cubes  can 
be  conveniently  formed  in  water  at  the  temperature  specified. 

3.  Pitches  have  melting-points  above  77°  C. 


Pf/-cfy 


FIG.  53. 


It  is  usually  necessary  to  heat  these  pitches  in  order  to  form 
the  cube.  For  this  purpose  a  copper  cup  of  approximately  50 
cubic  centimeters  capacity,  i'J/£  inches  deep  and  il/2  inches 
diameter,  provided  with  wooden  handle,  can  be  used.  The 
cup  should  be  half-filled  with  pitch  and  heated  carefully,  avoid- 
ing noticeable  evolution  of  vapors,  and  the  heating  should  not 


208 


be  continued  any  longer  than  absolutely  necessary.     An  oil 
bath  may  be  used  for  this  purpose. 


FIG.  54. 


For  these  pitches  an  air  bath  is  substituted  for  the  water 
bath.     The  hook  is  shorter,  so  that  the  cube  is  suspended  on  a 


2OQ 


line  running  through  the  center  of  the  observation  windows, 
the  thermometer  bulb  being  at  the  same  level.     The  tempera- 


FIG.  55. 


ture  of  the  oven  is  raised  5°  C.  each  minute,  as  usual,  and  the 
temperature  recorded  by  the  thermometer  at  the  instant  the 
pitch  drops  to  the  bottom  of  the  oven,  is  considered  the  melt- 


2IO 


ing-point.  To  make  results  by  this  method  comparable  with 
results  obtained  in  water,  6.5°  C.  should  be  added  to  the  ob- 
served melting-point.  (Important. — Results  by  this  method 
are  not  directly  comparable  with  results  obtained  in  water,  but 
are  always  lower.) 


FIG.  56. 


NOTE:. — Melting-point  apparatus  should  be  set  up  in  a  place 
free  from  drafts,  and  if  necessary,  protected  by  means  of  a 
shield  set  apart  from  the  apparatus. 


Same  as  4~b. 
Same  as  S-b. 
Same  as  4~d. 


9.  ROAD  TARS. 
a.  Distillation. 

b.  Specific  Gravity. 

c.  Free  Carbon. 

d.  Viscosity. 


Taken  in  the  Engler  viscosimeter  at  the  temperature  re- 
quired by  specifications.  The  full  quantity,  250  cubic  centi- 
meters, is  placed  in  the  apparatus  and  raised  to  the  tempera- 
ture at  which  it  is  desired  to  make  the  test.  One  hundred  cubic 
centimeters  are  then  permitted  to  flow  into  a  graduated  flask 
of  the  above  capacity,  and  the  time  of  flow  in  seconds  noted. 


211 


e.  Float  Test. 

Apparatus. — Consists  of  two  parts,  an  aluminum  float  or 
saucer,  and  a  conical  brass  collar.     (Fig.  57.) 


FIG.  57. 

Method. — The  brass  collar  is  placed  upon  a  brass  plate,  the 
surface  of  which  has  been  amalgamated,  and  filled  with  the  bitu- 
minous material  under  examination,  after  it  has  been  softened 
sufficiently  to  flow  freely  by  gentle  heating.  The  collar  must 
be  level-full,  and  as  soon  as  the  bitumen  has  cooled  sufficiently 
to  handle,  it  is  placed  in  ice  water  at  4°  C.  for  15  minutes.  It 
is  then  attached  to  a  float  and  immediately  placed  upon  the 
surface  of  the  water,  which  is  maintained  at  the  desired  tem- 
perature. 

As  the  plug  of  bitumen  in  the  brass  collar  becomes  warm 
and  fluid,  it  is  gradually  forced  out  of  the  collar,  and  as  soon 
as  the  water  gains  entrance  to  the  saucer  the  entire  apparatus 
sinks  below  the  surface  of  same. 

The  time  elapsing  between  placing  the  apparatus  on  the 
water  and  when  the  water  breaks  through  the  bituminous 
material  is  noted  by  means  of  a  stop  watch. 

10.    NAPHTHALENE  SALTS  (CRUDE  NAPHTHALENE). 
a.  Water. 

\Yeigh  200  grams  into  a  copper  still,  add  100  cubic  centi- 
meters of  water-free  naphtha  and  distil  up  to  210°  C.  vapor 
temperature.  Note  volume  of  water  as  in  similar  test  on  tar. 

b.  Solidifying  Point. 
If  water  is  present  it  must  be  removed  by  proper  distillation,. 


212 


as  in  creosote  oil.  About  20  cubic  centimeters  of  melted 
naphthalene  are  taken  in  a  test-tube  of  thin  glass  about  I  inch 
in  diameter  by  6  inches  long.  The  contents  are  thoroughly 
liquified  and  then  allowed  to  cool,  stirring  constantly  with  an 
accurate  thermometer.  As  permanent  crystals  begin  to  form, 
a  constant  temperature  is  held  for  a  short  time;  this  is  taken 
as  the  solidifying  point.  Often,  if  the  material  supercools, 
the  temperature  rises  as  the  solids  separate;  in  this  case  the 
highest  point  attained  on  the  rise  is  recorded.  The  higher 
the  solidifying  point  is,  the  longer  the  period  of  constant  tem- 
perature, and  hence  the  sharper  the  test. 

c.  Distillation. 

Weigh  100  grams  of  dried  naphthalene  into  a  regular  200 
cubic  centimeter  side-neck  distilling  bulb.  Connect  to  a  24- 
inch  condenser  tube  (from  the  water-in-tar-testing  apparatus). 
Water  cooling  should  not  be  used.  Use  a  standard  creosote 
oil  distillation  test  thermometer  and  collect  the  distillate  in  a 
100  cubic  centimeter  graduated  cylinder.  Conduct  the  test  as 
in  the  regular  bulb  distillation  of  naphthas  or  light  oils,  noting 
the  first  drop,  the  cubic  centimeters  distilled  every  10°  C. 
up  to  210°  C. ;  then  every  5°  C.  to  230°  C.  and  every  10°  C. 
up  to  the  decomposition  point.  This  is  indicated  by  the  ap- 
pearance of  white  fumes  in  the  flask.  During  the  course  of 
the  test,  the  condenser  tube  should  be  kept  warm  enough  to 
keep  the  distillate  liquid  by  playing  a  flame  over  it. 


CHAPTER  V. 

MISCELLANEOUS. 

WATER  ANALYSIS. 

Sampling. 

A  sample  of  water  should  not  be  taken  except  when  the 
supply  is  being  drawn  on  at  the  normal  operating  rate.  All 
taps  or  connections  through  which  the  sample  passes  must  be 
thoroughly  flushed  out.  The  vessel  to  contain  the  sample 
should  be  cleaned  with  care  and  then  thoroughly  rinsed  sev- 
eral times  with  the  water  to  be  sampled.  Metal  containers 
and  earthenware  jugs  may  contaminate  the  sample.  A  i- 
gallon  bottle  with  a  ground  glass  stopper  is  the  best  container 
for  samples  of  water. 

Total  Solids. — Evaporate  250  cubic  centimeters  to  dryness 
in  a  platinum  dish  (weighed),  dry  in  an  air  oven  at  100°  C. 
Cool  and  weigh. 

Organic  and  Volatile  Matter. — Ignite  the  contents  of  the 
dish  at  a  low  red  heat.  Cool  and  weigh.  The  loss  will  be 
organic  and  volatile  matter. 

Mineral  Solids. — Subtract  the  weight  of  the  dish  from  the 
weight  just  found  above.  The  difference  will  be  the  weight 
of  the  mineral  solids.  The  results  found  above  in  milligrams 
multiplied  by  4  will  be  the  parts  per  million. 

Alkalinity  or  Temporary  Hardness. — Measure  100  cubic 
centimeters  of  the  water  into  a  250  cubic  centimeter  glass- 
stoppered  bottle,  add  2.5  cubic  centimeters  Erythrosine  solu- 
tion (o.i  gram  of  the  sodium  salt  in  i  liter  distilled  water), 
and  5  cubic  centimeters  chloroform.  Add  N/5O  H2SO4  in 
small  quantities,  shaking  vigorously  at  each  addition.  The 
rose  color  gradually  disappears,  and  is  finally  entirely  dis- 
charged by  a  drop  or  two  of  the  acid.  A  white  paper  held 
behind  the  bottle  facilitates  the  detection  of  any  color  remain- 
ing as  the  end-point  is  reached.  The  number  of  cubic  centi- 
meters of  the  acid  used  multiplied  by  10  gives  the  number  of 
parts  per  million  alkalinity  in  terms  of  CaCO3. 


214 

Incrustants  or  Permanent  Hardness. — Measure  200  cubic 
centimeters  of  the  water  into  a  Jena  glass  Erlenmeyer  flask, 
boil  10  minutes  to  expel  free  CO2.  Add  25  cubic  centimeters 
of  N/io  soda  reagent  (equal  parts  of  N/io  NaOH  and  N/io 
Na2CO3),  and  boil  to  a  volume  of  100  cubic  centimeters. 
Cool  and  rinse  into  a  200  cubic  centimeter  graduated  flask, 
make  up  to  the  mark  with  boiled  distilled  water.  Filter,  and 
reject  the  first  50  cubic  centimeters.  Titrate  100  cubic  centi- 
meters of  the  remainder  for  excess  of  soda  reagent  with  N/2O 
HaSG4,  using  Erythrosine  as  an  indicator  as  above.  If  S 
equals  the  cubic  centimeters  of  N/2O  H2SO4  equivalent  to  the 
soda  reagent  used,  and  N  equals  the  cubic  centimeters  of  N/2O 
H2SO4  required  for  the  excess  or  back  titration,  then  the  in- 
crustants  in  parts  per  million  CaCO3  will  be:  12.5  (S  —  2N). 
Total  hardness  is  the  sum  of  the  alkalinity  and  incrustants. 

Mineral  Analysis.*  NOTE. — The  volume  taken  for  analysis 
depends  on  the  quantity  of  total  solids  present  in  the  water. 
The  calculations  of  the  following  method  are  based  on  a  vol- 
ume of  i  liter  of  water. 

Method. — Evaporate  I  liter  in  a  platinum  dish  to  about  5 
cubic  centimeters.  Filter  into  a  200  cubic  centimeter  gradu- 
ated flask.  Wash  with  successive  small  quantities  of  hot  dis- 
tilled water  by  putting  the  water  into  the  dish,  rinsing  it 
around  and  pouring  it  on  the  filter. 

The  solution  in  the  flask  contains  probably  Cl,  SO3,  Mg, 
alkalies,  and  Ca. 

The  residue  in  the  dish  and  on  the  filter  contains  probably 
Si02,  A1203,  Fe203,  CaCO3,  and  MgCOa. 

Treatment  of  the  Solution. — Cool  the  flask  and  fill  to  the 
mark  with  distilled  water.  Mix  well  and  divide  into  three 
parts. 

Part  a. — Fifty  cubic  centimeters  equivalent  to  250  cubic  cen- 
timeters original  water.  Determine  Cl  with  standard  AgNO3. 
Milligrams  Cl  multiplied  by  4  gives  parts  Cl  per  million. 

Part  b. — Fifty  cubic  centimeters  equivalent  to  250  cubic 
centimeters  original  water.  Slightly  acidify  with  HC1  and 
determine  SO3  by  precipitating  with  BaSO4.  BaSO4  multi- 


215 

plied  by  0.343  equals  SO3.  Milligrams  SO3  multiplied  by  4 
gives  parts  SO3  per  million. 

Part  c. — One  hundred  cubic  centimeters  equivalent  to  500 
cubic  centimeters  original  water.  Slightly  acidify  with  HC1. 
Make  faintly  alkaline  with  NH4OH,  boil,  and  add  ammonium 
oxalate,  allow  to  stand  over  night,  filter,  wash,  ignite,  and  weigh 
the  CaO.  CaO  multiplied  by  0.715  equals  Ca.  Milligrams  Ca 
multiplied  by  2  equals  parts  Ca  per  million.  Evaporate  the  fil- 
trate to  dryness  in  a  weighed  platinum  dish,  add  a  few  drops  of 
H2SO4  and  ignite  until  white  fumes  are  all  driven  off.  Cool 
and  weigh  as  MgSO4  +  Na2SO4.  Dissolve  in  warm  water, 
filter  if  necessary,  acidify  slightly  with  HC1.  Place  beaker 
in  a  dish  cooled  with  ice,  add  5  cubic  centimeters  sodium  phos- 
phate, then  make  strongly  alkaline  with  ammonia.  Stir  for 
about  3  minutes  and  set  aside  over  night.  Filter,  and  wash 
with  water  containing  10  per  cent.  NH4OH  and  10  per  cent. 
NH4NO3.  Dry  in  an  oven.  Ignite  in  a  porcelain  crucible. 
Weigh  as  Mg2P2O7.  Mg2PaO7  multiplied  by  0.362  gives  MgO. 
Milligrams  MgO  multiplied  by  2  gives  parts  MgO  per  million. 
Mg2PeO7  multiplied  by  1.0814  gives  MgSO4,  which  deducted 
from  the  contents  of  the  dish  found  above  gives  Na2SO4. 
Na2SO4  multiplied  by  0.324  gives  Na2.  Milligrams  Na2  mul- 
tiplied by  2  gives  parts  Na  per  million  in  the  water. 

NOTE;. — The  chlorine  found  may  be  checked  in  two  ways : 

1.  By  dissolving  the  contents  of  the  dish  in  mineral  solids 
in  H2O,  and  titrating  with  standard  AgNO3. 

2.  By  taking  100  cubic  centimeters  of  the  original  water, 
boiling    out    the    Col2,    cooling    and    titrating    with    standard 
AgN03. 

Calculations  from  above : 
Calculate  Na  to  NaCl. 
Cl  remaining  to  MgCl2. 
Cl  remaining  to  CaCl2. 
Mg  remaining  to  MgSO4. 
SO3  remaining  to  Na2SO4. 

Residue  in  Dish  and  on  Filter  Paper. — Place  filter  and  con- 
tents in  the  dish,  dry  over  a  Bunsen  burner  flame,  care- 


2l6 

fully  burn  paper,  and  ignite  to  burn  off  carbon.  Add  a  little 
HC1  and  rinse  around  the  dish.  Evaporate  to  dryness,  redis- 
solve  in  a  little  acid,  and  evaporate  again  to  dryness.  Take 
up  again  with  a  little  acid,  add  water,  boil  and  filter  into  a 
200  cubic  centimeter  graduated  flask.  Wash  thoroughly. 
Dry,  ignite,  and  weigh  the  filter  in  a  platinum  crucible;  this 
gives  SiO2;  milligrams  of  which  equals  parts  per  million  in 
the  original  water.  Cool  the  flask  and  contents,  fill  to  the 
mark  with  distilled  water  and  mix  well.  Divide  this  solution 
into  two  parts. 

Part  a. — Fifty  cubic  centimeters  equivalent  to  250  cubic 
centimeters  of  original  water.  Determine  SO3  as  BaSO4,  as 
before  described.  BaSO4  multiplied  by  0.343  equals  SO3. 
Milligrams  SO3  multiplied  by  4  equals  parts  per  million  in 
original  water. 

Part  b. — One  hundred  fifty  cubic  centimeters  equivalent  to 
750  cubic  centimeters  original  water.  Add  a  few  drops 
of  HNO3  and  boil.  Make  faintly  alkaline  with  ammonia  and 
boil  until  odor  of  ammonia  has  gone.  Filter  off  Al  and  Fe 
hydroxides,  wash,  dry,  ignite  and  weigh  as  A12O3  -j-  Fe2O3. 
Milligrams  of  AleO3  divided  by  Fe2O3  multiplied  by  4/3  equal 
parts  per  million  in  the  original  water. 

Filtrate. — Boil,  add  ammonium  oxalate,  and  allow  to  stand 
for  4  hours,  filter,  wash  with  hot  water,  dry,  ignite  in  a  plati- 
num crucible,  finishing  over  a  blast  lamp  to  constant  weight. 
Milligrams  CaO  multiplied  by  4/3  equal  parts  CaO  per  mil- 
lion in  the  original  water. 

Filtrate. — Concentrate  to  about  50  cubic  centimeters  adding 
HNO3  to  destroy  the  NH4C1  if  necessary,  precipitate  Mg2P2O7 
as  usual.  Mg2P2O7  multiplied  by  0.362  gives  MgO,  milligrams 
of  which  multiplied  by  4/3  equal  parts  per  million  in  the 
original  water. 

Calculations  from  above : 
Calculate  SO3  to  CaSO4. 
Calculate  CaO  remaining  to  CaCO3. 
Calculate  MgO  to  MgCO3. 


PAINTS. 

Analysis  of  Red  Holder  Paint. 

Weigh  out  0.5  gram  of  the  dry  pigment  after  extraction  of 
the  vehicle  in  a  porcelain  casserole  and  add  50  cubic  centi- 
meters HC1  (i :  i).  Boil  gently  for  15  minutes,  evaporate  to 
dryness  on  the  sand  bath,  moisten  with  concentrated  HC1,  and 
evaporate  again.  Moisten  again  with  concentrated  HC1,  add 
100  cubic  centimeters  of  water  and  boil  gently  for  a  few  min- 
utes. Filter,  wash,  ignite  and  weigh  as  silica,  SiO2,  etc.  Add 
a  few  drops  of  H2SO4  to  the  residue  and  a  little  HC1,  and 
evaporate  gently  on  a  sand  bath  under  the  hood.  The  loss  in 
weight  represents  SiO2 ;  any  residue  remaining  should  be  fused 
with  potassium  bisulphate  and  dissolved  in  HC1  and  filtered. 
Any  residue  remaining  on  the  filter  is  BaSO4,  which  is  ignited 
and  weighed.  The  filtrate  is  added  to  the  filtrate  from  the 
silica.  This  procedure  is  only  necessary  in  case  of  a  large 
per  cent,  of  insoluble.  Otherwise,  report  as  insoluble  matter. 
The  combined  filtrates  are  made  up  to  250  cubic  centimeters 
and  an  aliquot  portion  taken,  made  alkaline  with  NH4OH, 
boiled,  filtered,  washed,  ignited,  and  weighed  as  Fe2O3  and 
A12O3.  Take  another  portion  and  precipitate  with  ammonia 
as  before.  Filter  and  wash,  and  dissolve  the  precipitate  on 
the  paper  with  10  per  cent.  H^SC^  into  a  flask.  Add  a  few 
pieces  of  zinc,  stopper  flask  with  a  stopper  fitted  with  a  Bun- 
sen  valve  and  allow  to  stand  until  all  the  iron  is  reduced. 
Then  filter  off  the  zinc  and  add  10  cubic  centimeters  H2SO4, 
and  titrate  with  N/io  KMnO4,  calculating  to  Fe,2O3.  The 
difference  between  these  gives  A12O3.  The  filtrate  from  the 
iron  and  alumina  is  heated  to  boiling,  ammonium  oxalate 
added,  set  aside  on  the  sand  bath  over  night,  filtered,  ignited 
and  weighed  as  CaO.  If  any  magnesium  is  present,  pre- 
cipitate with  sodium  hydrogen  phosphate  in  the  filtrate  from 
the  calcium  as  usual.  Determine  SO3  water  of  hydration,  and 
CO2  as  usual  in  separate  samples. 

Method  of  Analysis  of  Green  Pigments. 
Weigh  out  i  gram  into  a  200  cubic  centimeter  Jena  beaker 


2l8 

and  ignite  gently  to  decompose  the  Prussian  blue.  Cool  the 
beaker,  add  25  cubic  centimeters  ( I :  I )  HC1,  boil  to  dissolve 
the  iron  oxide  and  expel  the  excess  of  acid.  Dilute  with 
water  and  filter  off  the  insoluble  matter. 

Insoluble  Part. — Ignite  in  a  platinum  crucible  and  weigh. 
Add  fusing  mixture  and  fuse  to  decompose  the  clay  and  bari- 
um sulphate.  Extract  the  fusion  with  water,  dissolve  the  in- 
soluble residue  in  HC1  and  determine  the  barium  as  sulphate 
in  the  acid  solution. 

Soluble  Part. — Nearly  neutralize  the  acid  with  ammonia 
and  precipitate  the  lead  as  sulphide  with  H2S.  Filter  off  the 
precipitate,  dissolve  in  HNO3,  and  determine  the  lead  as  sul- 
phate or  chromate.  Boil  the  filtrate  to  expel  H2S  and  pre- 
cipitate the  iron,  aluminum  and  chromium  with  ammonia. 
Filter  off  the  precipitate  and  in  the  solution  determine  the  cal- 
cium as  usual.  Dissolve  the  combined  hydrates  in  HC1  and 
dilute  the  solution  to  100  cubic  centimeters  with  water.  Take 
50  cubic  centimeters  and  reprecipitate  the  metals  with  am- 
monia. Filter,  ignite  and  weigh  as  oxides.  Oxidize  the  chro- 
mium in  the  second  50  cubic  centimeter  portion  by  a  careful 
addition  of  Na2O2.  Boil  the  solution  to  decompose  the  ex- 
cess of  peroxide,  dilute  with  water  and  filter  off  the  ferric 
hydrate.  The  filtrate  will  contain  the  chromium  as  chromate 
and  aluminum  as  aluminate  of  sodium. 

Dissolve  the  ferric  hydrate  in  acid,  reduce  with  zinc  and 
titrate  with  N/io  KMnO4.  Acidify  the  chromium  solution 
with  H2SO4,  add  excess  of  ferrous  sulphate  and  titrate  the 
unoxidized  iron  with  KMnO4  N/io.  From  the  amount  of 
FeSO4  used  up  to  reduce  the  chromate,  calculate  the  per  cent, 
of  chromium.  Calculate  the  iron  and  chromium  to  oxides  and 
subtract  from  the  weight  of  the  combined  oxides.  The  alu- 
mina is  found  by  difference.  Calculate  the  iron  to  Prussian 
blue,  and  chromium  to  lead  chromate.  Determine  the  soluble 
SO3  and  water  of  hydration  in  separate  samples. 


219 

PAINT  VEHICLES. 

Method  of  Analysis  of  a  Mixture  Consisting  of  Benzene,  Tur- 
pentine, Fatty  Oils,  Rosin  Oil,  and  Petroleum. 

1.  Distil  off  and  collect  the  benzene  and  turpentine,  using 
either  a  current  of  CO2,  Note  A,  or  of  steam,  Note  B.     Sep- 
arate them  by  fractional  distillation,  Note  C,  by  the  action  of 
HNO3,  Note  D,  or  of  H2SO4,  Note  E. 

2.  Saponify  the  fatty  oils  in  the  residue,  Note  F,  with  caus- 
tic KOH  in  the  usual  manner.     Dissolve  the  saponified  mat- 
ter in  water,  Note  G,  and  the  unsaponified  oils  in  ether.     Sep- 
arate carefully,  washing  the  aqueous  solution  with  ether,  and 
the  ethereal  solution  with  water. 

3.  Evaporate   off  the   ether   and   weigh   the   rosin   oil   and 
petroleum  oil.    Treat  with  HNO3,  Note  H,  extract  the  resid- 
ual petroleum  oil  with  ether,  evaporate  the  latter  and  weigh. 
Rosins,  if  present,  would  be  saponified  with  the  fatty  oils, 
and  might  be  estimated  in  the  soap  solution  by  Cladding's 
method.     Tar  oil  would  probably  accompany  the  rosin  oil  in 
the  above  scheme. 

NOTE  A. — Turpentine  can  be  distilled  according  to  H.  J. 
Phillips,  Chem.  News,  63,  275,  and  Jour.  Chem.  Ind.  10,  577, 
at  about  220°  using  about  150  grams  of  the  sample  and  passing 
through  it  a  current  of  CO2  to  prevent  oxidation  of  the  lin- 
seed oil.  The  temperature  required  by  this  method  is  higher 
than  that  used  in  steam  distillation,  and  in  most  cases  the 
latter  would  probably  be  preferable. 

NOTE  B. — In  the  steam  distillation,  use  about  25  grams  of 
the  sample  in  a  400  cubic  centimeter  flask  with  a  few  pieces 
of  glass  or  metal  to  prevent  bumping.  Maintain  at  a  tempera- 
ture of  about  110°  and  when  the  turpentine  is  all  removed, 
continue  the  heating  long  enough  to  remove  the  last  portions 
of  water.  The  weight  of  the  residue  may  then  be  taken  to 
check  the  results.  The  distillate  is  allowed  to  stand,  the  tur- 
pentine and  benzene  are  separated  from  the  water  and 
weighed,  and  to  the  result  is  added  o.ioo  gram  of  turpentine 
for  every  30  cubic  centimeters  of  water  in  the  distillate.  Ac- 


220 

cording  to  Mcllhiney,  Jour.  Am.  Chem.  Soc.,  16,  348,  this 
method  gives  very  accurate  results. 

NOTE  C. — In  case  of  a  mixture  of  turpentine  with  light  ben- 
zene, a  rough  separation  may  be  effected  by  fractional  distilla- 
tion, since  the  turpentine  distils  mainly  between  150°  to  180°. 
A  method  which  is  not  affected  by  the  boiling-point  of  ben- 
zene is  that  of  separation  by  means  of  acids. 

NOTE  D. — The  HNO3  method  for  separating  benzene  and 
turpentine,  due  to  Burton,  Am.  Chem.  Jour.,  12,  102,  is  thus 
described  by  Phillips,  Eng.  Chem.,  p.  273 :  A  balloon  flask  of 
750  cubic  centimeters  capacity  is  fitted  with  a  two-hole  cork 
stopper.  Connect  with  a  dropping  funnel  and  an  inverted 
condenser.  About  300  cubic  centimeters  fuming  HNO3  of  1.4 
specific  gravity  are  placed  in  the  flask  and  100  cubic  centi- 
meters of  the  turpentine  to  be  tested  are  measured  into  the 
dropping  funnel.  The  flask  is  surrounded  by  cold  water  and 
the  turpentine  allowed  to  drop  slowly  into  the  HNO3.  As 
each  drop  strikes  the  acid,  a  violent  action  takes  place  with 
the  evolution  of  red  fumes.  Shake  occasionally,  and  when  all 
the  turpentine  has  been  added,  allow  to  stand  until  all  action 
is  over.  Transfer  to  a  separatory  funnel  and  wash  with  hot 
water.  Finally  separate  and  measure  and  weigh  the  benzene. 

NOTE  E. — Armstrong's  method  for  the  separation  of  ben- 
zene from  turpentine,  Jour.  Soc.  Chem.  Ind.,  I,  480,  depends 
upon  the  polmerization  of  the  latter  by  H2SO4.  This  method 
is  given  by  Allen,  Com.  Org.  Andy.,  n,  441,  but  it  is  more 
time  consuming  than  the  HNO3  process  and  probably  no  more 
accurate. 

NOTE  F. — This  residue  may  be  dried  and  weighed.  If  it 
shows  signs  of  alteration  as  a  result  of  the  steam  distillation, 
another  portion  may  be  freed  from  turpentine  by  exhaustion 
of  the  air  and  gentle  heating.  In  this  case,  it  is  necessary 
after  removing  most  of  the  turpentine,  to  add  a  little  petro- 
leum ether  of  very  low  boiling-point.  This,  in  distilling,  car- 
ries the  last  of  the  turpentine  with  it.  A  residue  prepared  in 
this  way  may  be  found  in  better  condition  for  further  ex- 
amination than  one  obtained  by  steam  distillation. 


221 

NOTE;  G. — If  the  amount  of  fatty  oil  is  not  found  by  differ- 
ence, it  can  be  estimated  by  separating  the  fatty  acids,  weigh- 
ing and  them,  and  estimating  the  corresponding  weight  of  gly- 
cerides.  If  resin  is  present,  the  resin  acids  are  determined  by 
Cladding's  method.  If  the  fatty  oils  present  are  not  more 
than  two  in  number,  an  approximate  estimate  of  the  amount 
of  each  may  be  deducted  from  the  determination  of  such  con- 
stants as  Hubl,  Koettsdorfer,  and  acetyl  figures  on  the  sepa- 
rated fatty  acids. 

NOTE  H. — According  to  Mcllhiney,  Jour.  Am.  Chem.  Soc., 
*6,  385,  the  following  process  gives  fairly  accurate  results : 

Fifty  cubic  centimeters  HNO3  of  1.2  specific  gravity  are 
heated  to  boiling  in  a  flask  of  700  cubic  centimeters  capacity. 
The  source  of  heat  is  removed  and  5  grams  of  the  oil  to  be 
analyzed  added.  The  flask  is  then  heated  on  the  water  bath 
with  frequent  shaking  for  15  to  20  minutes,  and  about  400 
cubic  centimeters  of  cold  water  added.  After  the  liquid  has 
become  entirely  cold,  50  cubic  centimeters  of  petroleum  ether 
are  added  and  the  flask  agitated.  The  petroleum  oil  is  un- 
changed and  dissolves  in  the  ether.  This  solution  is  poured 
into  a  separatory  funnel,  leaving  the  lumps  of  solid  resin  as 
far  as  possible  in  the  flask.  After  settling,  the  aqueous  liquid 
is  drawn  off  and  the  ethereal  layer  poured  into  a  tared  flask. 
The  resin  is  washed  with  another  portion  of  petroleum  ether, 
which  is  added  to  the  first.  The  ether  is  then  evaporated  and 
the  oil  weighed.  Since  mineral  oils  lose  about  10  per  cent,  in 
this  wray,  the  weight  of  oil  found  must  be  divided  by  0.9  to 
obtain  the  correct  value. 

FIRE  CLAY  AND  REFRACTORIES. 
Chemical  Analysis. 

Since  the  heat  resistance  as  well  as  the  strength  of  refrac- 
tories depends  largely  on  its  chemical  composition,  an  analysis 
can  in  most  cases  help  to  distinguish  between  good,  mediocre 
or  bad  refractories.  It  will  also  help  to  ascertain  the  cause  of 
failures. 
15 


222 


Aside  from  physical  tests  it  is  of  utmost  importance  to  as- 
certain the  chemical  composition  of  refractories.  The  follow- 
ing elements  or  rather  their  oxides,  etc.,  are  to  be  considered 
silica,  alumina,  ferrous  and  ferric  oxides,  calcium,  magnesium, 
alkalies,  also  in  clay,  manganese  oxide,  sulphur  trioxide,  car- 
bon dioxide,  silica.  Dissolving  in  acids  is  in  most  cases  im- 
possible. It  is  therefore  advisable  to  fuse  in  a  platinum  cruci- 
ble I  gram  of  the  very  finely  powdered  sample  and  5  grams 
of  a  fusing  mixture  (sodium  carbonate  4  parts,  potassium  ni- 
trate i  part).  The  fusion  is  complete  as  soon  as  the  evolu- 
tion of  the  gas  ceases.  The  crucible  is  next  transferred  to  a 
porcelain  casserole  and  the  fusion  dissolved  in  hot  water  to 
which  a  few  drops  of  hydrochloric  acid  are  added  from  time 
to  time.  After  the  fusion  has  been  dissolved,  remove  plati- 
num crucible  carefully,  washing  inside  and  outside  well  into 
the  casserole.  Care  must  be  taken  that  the  content  of  the 
casserole  is  acid.  Evaporate  to  dryness,  bake  for  a  short 
time  at  about  120°  C.  until  all  the  HC1  has  been  driven  off. 
Wash  the  precipitate  on  the  filter  paper  about  3  to  5  times 
with  hot  dilute  HC1  and  then  with  hot  water  until  no  more 
precipitate  is  formed  by  adding  a  drop  of  silver  nitrate  to 
the  filtrate  collected  in  a  test-tube,  after  removing  beaker  con- 
taining the  bulk  of  filtrate.  Dry  both  filter  papers  in  a  tared 
platinum  crucible,  burn  and  weigh  the  SiO2.  The  silica 
should  be  perfectly  white.  If  there  is  any  indication  of  color 
due  to  impurities  it  is  best  to  add  a  few  drops  of  sulphuric 
acid  to  the  silica  and  then  add  drop  by  drop  hydrofluoric  acid 
until  no  more  reaction  takes  place.  Add^a  slight  excess  and 
evaporate  to  dryness,  heat  over  a  Bunsen  burner,  cool  and 
weigh.  Deduct  this  weight  from  the  weight  of  crucible  and 
precipitate.  This  gives  the  correct  weight  of  SiO2.  The 
residue  in  the  platinum  crucible  generally  consists  of  iron 
oxide.  It  is  dissolved  in  HC1  and  added  to  the  bulk  of  fil- 
trate from  SiO2.  The  filtrate  is  next  transferred  to  a  500 
cubic  centimeter  graduated  flask  and  made  up  to  500  cubic 
centimeters  and  well  stirred.  One  hundred  cubic  centimeters 
of  the  solution  are  transferred  to  a  beaker,  about  10  cubic 


223 

centimeters  of  sulphuric  acid  added,  and  the  whole  evaporated 
until  all  the  HC1  has  been  driven  off.  It  is  next  diluted  with 
water  and  reduced  with  zinc.  (The  most  satisfactory  method 
is  a  Jones  reducteur,  but  stick  zinc  will  do  where  a  Jones 
reducteur  is  not  available)  and  titrated  with  a  standard  solu- 
tion of  potassium  permanganate.  The  iron  factor  of  the  per- 
manganate multiplied  by  1.429  gives  the  factor  for  Fe2O3. 
The  results  multiplied  by  5  gives  the  per  cent,  of  iron  oxide 
in  the  sample. 

Phosphoric  Acid. — In  another  100  cubic  centimeters  of  the 
solution  the  phosphoric  acid  is  determined  by  precipitation 
with  molybdic  acid  solution.  (For  preparing  the  solution  see 
analysis  of  iron  and  steel.)  Twenty  to  25  cubic  centimeters 
are  added  to  the  100  cubic  centimeters  of  the  nitrate  from 
the  silica  and  transferred  to  a  300  cubic  centimeter  Erlen- 
meyer  flask.  After  vigorously  shaking  for  5  minutes,  the 
flask  is  stood  aside  for  the  precipitate  to  settle.  After  the 
solution  has  cleared  it  is  filtered  through  a  close-grained 
paper,  the  flask  and  precipitate  are  washed  with  a  dilute  solu- 
tion of  ammonium  sulphate  made  slightly  acid  with  sulphuric 
acid.  After  washing  it  is  redissolved  in  ammonia  into  the 
flask  in  which  it  had  been  precipitated.  It  is  then  reduced 
with  zinc  and  titrated  with  standard  permanganate  solution 
as  under  iron  (for  factor  see  Iron  and  Steel). 

Alumina. — To  the  remaining  300  cubic  centimeters  add, 
after  transferring  to  a  600  cubic  centimeter  beaker,  sufficient 
ammonia  to  have  a  slight  excess  of  the  latter,  boil  off  excess 
and  filter  off  the  precipitated  iron  and  aluminum  oxides,  wash 
with  water,  dry  and  burn  off  in  a  tared  porcelain  crucible. 
From  the  weight,  subtract  the  iron  oxide  and  phosphoric  acid 
previously  determined.  The  rest  is  alumina. 

Calcium. — To  the  filtrate  from  the  iron  and  aluminum 
oxides  add  a  solution  of  ammonium  oxalate,  and  heat  to  boil- 
ing. The  precipitated  calcium  oxalate  is  filtered  off  and 
washed.  The  filter  paper  is  next  transferred  to  a  weighed 
porcelain  crucible,  a  few  drops  of  sulphuric  acid  are  added, 


224 

and  it  is  then  dried  and  burned.  The  calcium  oxide  is  calcu- 
lated from  the  weight  of  the  calcium  sulphide  thus  formed. 

Magnesia. — In  the  filtrate  from  the  calcium  oxalate  the 
magnesia  is  determined.  The  nitrate  is  first  concentrated  to 
about  250  cubic  centimeters.  It  is  then  cooled  and  placed  in 
a  dish  containing  ice  water.  A  solution  of  sodium  ammo- 
nium phosphate  and  about  30  cubic  centimeters  ammonia  are 
added,  and  the  solution  vigorously  stirred.  Care  should  be 
taken  not  to  touch  the  sides  of  the  beaker  with  the  rod.  The 
solution  is  left  standing  for  about  10  hours,  and  the  mag- 
nesium pyrophosphate  is  then  filtered  and  washed  with  a  dilute 
solution  of  ammonium  nitrate  made  slightly  alkaline  with  am- 
monia. The  precipitate  of  magnesium  pyrophosphate  is  next 
dried  and  burned  and  weighed  as  Mg2P2O7  from  which  the 
MgO  is  calculated. 

Alkalies. — For  the  alkalies  place  2  grams  of  the  finely 
divided  sample  into  a  platinum  dish,  moisten  with  about  2 
cubic  centimeters  of  concentrated  sulphuric  acid,  then  add 
hydrofluoric  acid  until  reaction  ceases.  Add  a  small  excess 
and  heat  to  drive  off  excess,  until  white  fumes  of  sulphurous 
acid  are  given  off.  Cool,  add  water,  and  wash  into  a  beaker. 
Add  10  cubic  centimeters  of  hydrochloric  acid  and  boil.  Pre- 
cipitate iron  and  alumina  with  ammonia,  and  then  add  a  solu- 
tion of  ammonium  oxalate  to  precipitate  calcium,  boil  and 
filter  off  precipitate  and  wash  with  hot  water.  Discard  filter 
paper  and  precipitate.  Evaporate  filtrate  in  a  weighed  plati- 
num dish  and  after  the  solution  has  been  evaporated  to  dry- 
ness,  heat  over  a  Bunsen  flame.  The  residue  consists  of  al- 
kaline and  magnesium  sulphates ;  calculate  the  magnesium 
previously  determined  to  sulphate  and  deduct  from  weight  of 
dish.  The  difference  between  this  corrected  weight  and  the 
original  weight  of  the  dish  are  alkaline  sulphates. 

Sulphur  Trioxide. — Two  grams  of  the  finely  divided  sample 
are  for  12  hours  digested  in  hydrochloric  acid,  to  which  potas- 
sium chlorate  is  added.  It  is  finally  taken  down  to  dryness, 
redissolved  in  HC1,  and  the  insoluble  part  filtered  off.  The 
filtrate  is  heated  to  boiling,  barium  chloride  added,  and  then 


225 

cooled.  After  the  solution  has  cleared  the  barium  sulphate  is 
filtered,  washed,  transferred  to  a  weighed  crucible  and  burned. 
From  the  weight,  the  sulphur  trioxide  is  calculated. 

Titanium. 

To  determine  titanic  acid,  treat  2  grams  of  the  finely  ground 
clay  in  a  large  platinum  crucible  with  hydrofluoric  acid  and  5 
cubic  centimeters  of  sulphuric  acid.  Evaporate  off  the  hydro- 
fluoric acid  and  heat  carefully  until  the  greater  part  of  the  sul- 
phuric acid  is  volatilized.  Allow  the  crucible  to  cool,  add  10 
grams  of  sodium  carbonate,  and  fuse  for  30  minutes  at  the 
highest  temperature  obtainable  by  a  Bunsen  burner.  Run  the 
fused  mass  well  up  on  the  sides  of  the  crucible,  and  allow  it  to 
cool.  Treat  the  fused  mass  with  water,  transfer  it  to  a 
beaker,  and  filter.  Wash  the  insoluble  matter  slightly  on  the 
filter,  dry,  ignite,  and  fuse  it  again  with  sodium  carbonate. 
Dissolve  in  water  as  before,  and  filter.  By  this  method  of 
treatment  nearly  all  of  the  alumina  will  be  dissolved  and  sepa- 
rated from  the  titanic  acid.  Fuse  the  insoluble  matter  left  on 
the  filter  with  sodium  carbonate.  Dissolve  in  hot  water,  filter 
off  insoluble  ferric  oxide,  etc.,  acidulate  with  HC1,  add  a  few 
drops  of  acid  ammonium  sulphite,  boil  off  all  smell  of  sul- 
phurous acid,  and  pass  hydrogen  sulphide,  through  the  hot 
solution  to  precipitate  any  arsenic  that  may  be  present.  Pass 
a  current  of  carbonic  acid  through  the  solution  to  expel  the 
excess  of  hydrogen  sulphide,  filter  off  the  arsenious  sulphide, 
and  to  the  filtrate  add  a  sufficient  amount  of  ferric  chloride 
solution  to  combine  with  all  the  phosphoric  acid  as  ferric 
phosphate  and  leave  a  slight  excess.  Add  a  slight  excess  of 
ammonia,  which  should  throw  down  a  red  precipitate,  while 
the  solution  is  alkaline  to  test-paper;  then  add  acetic  acid  to 
slightly  acid  reaction,  boil,  filter  off  the  ferric  phosphate  and 
ferric  oxide,  and  wash  with  hot  water.  Acidulate  the  filtrate 
with  HC1,  add  ammonia  until  a  permanent  precipitate  forms, 
redissolve  with  a  few  drops  of  hydrochloric  acid,  add  a  fil- 
tered solution  of  20  grams  of  sodium  acetate  and  one-sixth  the 
volume  of  the  solution  of  acetic  acid  (1.04  specific  gravity) 


226 

and  heat  to  boiling.  The  titanic  acid  is  precipitated  almost 
immediately  in  a  flocculent  condition  and  quite  free  from  iron. 
Boil  a  few  minutes,  allow  the  titanic  acid  to  settle,  filter,  wash 
with  hot  water  containing  a  little  acetic  acid,  dry,  ignite,  and 
weigh  as  titanic  acid,  which  contains  60.05  per  cent,  titanium. 
Should  the  precipitate  contain  an  appreciable  amount  of  ferric 
oxide,  fuse  with  bisulphate  and  reprecipitate  in  the  same  way. 

The  essential  points  in  this  method  are:  I.  Separation  of 
the  titanic  acid  from  the  mass  of  ferric  oxide  by  ammonium 
acetate  in  the  deoxidized  solution.  2.  Separation  from  all  the 
phosphoric  acid  and  the  greater  part  of  the  alumina  by  fusion 
with  sodium  carbonate,  by  which  means  a  sodium  titanate  in- 
soluble in  water  is  formed,  and  at  the  same  time  sodium  phos- 
phate and  aluminate  soluble  in  that  menstruum.  3.  Separation 
of  the  last  traces  of  alumina  from  the  ferric  oxide,  lime,  etc., 
by  precipitating  the  titanic  acid  in  the  thoroughly  deoxidized 
solution  in  the  presence  of  a  large  excess  of  acetic  acid  and 
some  sulphurous  acid,  the  sulphuric  acid  being  all  in  the  form 
of  sodium  sulphate.  The  addition  of  a  large  excess  of  sodium 
acetate,  by  which  this  latter  condition  is  effected,  converts  all 
the  sulphate  into  acetates,  and  precipitates  the  titanic  acid  al- 
most instantaneously  as  a  hydrate,  which  is  flocculent,  settles 
quickly,  shows  no  tendency  to  run  through  the  filter,  and  is 
washed  with  the  greatest  ease.  It  sometimes  happens  that  a 
little  ferrous  oxide  is  precipitated  with  the  titanic  acid,  and 
the  latter,  after  ignition,  appears  discolored;  in  this  case  fuse 
with  a  little  sodium  carbonate,  add  sulphuric  acid  to  the  cold 
fused  mass,  dissolve,  and  repeat  the  precipitation  with  sodium 
acetate  in  the  presence  of  sulphurous  and  acetic  acids  exactly 
as  in  the  first  instance. 

The  above  titanium  method  is  taken  from  "The  Chemical 
Analysis  of  Iron,"  by  Blair. 

Sutton  gives  the  following  volumetric  method : 

H.  L,.  Wells  and  W.  L.  Mitchell,  in  a  contribution  to  the 
Jour.  Amer.  Chem.  Soc.  1895,  878,  allude  to  a  volumetric 
method  of  determining  titanic  acid  by  Pisani  (Compt.  Rend, 
lix.  289)  which  does  not  appear  to  have  been  found  satis- 


227 

factory.  Marignac  (Zeit.,  anal.  Cheni.  vii.  112)  applied 
Pisani's  method  in  the  estimation  of  titanic  acid  in  the  presence 
of  niobic  acid,  special  conditions  being  adopted  to  avoid  the 
reduction  of  the  latter. 

The  authors  have  modified  Pisani's  process  as  improved  by 
Marignac,  and  employ  it  for  the  determination  of  iron  together 
with  the  titanic  acid  in  ores.  Sulphuric  acid  solutions  are 
used,  and  the  liquid  is  protected  from  the  air  during  cooling 
and  titration  by  means  of  a  current  of  carbon  dioxide. 

Process. — Five  grams  of  the  pulverized  ore  are  treated  with 
100  cubic  centimeters  of  concentrated  hydrochloric  acid  in  a 
covered  beaker,  using  a  gradually  increasing  heat,  and 
adding  more  acid  if  necessary.1  When  there  is  no  further 
action,  50  cubic  centimeters  of  a  mixture  of  equal  volumes  of 
sulphuric  acid  and  water  are  added,  and  the  liquid  evaporated 
until  it  fumes  strongly.  After  cooling,  200  cubic  centimeters 
o*f  water  are  added,  the  whole  heated  until  the  sulphates  dis- 
solve, and  the  liquid  filtered  into  a  liter  flask.  If  anything  be- 
sides silicious  matter  is  left  on  the  filter  paper,  it  should  be 
fused  with  potassium  bisulphate,  treated  with  concentrated 
sulphuric  acid,  and  the  sulphates  dissolved  in  hot  water  and 
added  to  the  main  solution. 

The  liquid  in  the  flask  is  made  up  to  the  mark  with  water, 
and  four  portions  of  200  cubic  centimeters  each  taken,  two 
in  Erlenmeyer  flasks  (500  cubic  centimeters),  and  the  other 
two  in  ordinary  350  cubic  centimeter  flasks.  Each  of  these 
represents  I  gram  of  the  ore. 

To  determine  the  iron,  H2S  is  passed  into  the  solutions  in 
the  ordinary  flasks  to  saturation,  after  which  they  are  boiled 
until  all  the  H2S  has  been  removed,  care  being  taken  to  avoid 
any  contact  of  the  solution  with  the  air  by  covering  the  mouths 
of  the  flasks  with  crucible  lids.  The  flasks  are  then  quickly 
filled  to  the  neck  with  cold  recently-boiled  water,  rapidly 
cooled,  transferred  to  large  beakers,  and  titrated  with  standard 
potassium  permanganate. 

1  For  refractories  it  appears  advisable  to  treat  with  HF1  and  H2SO4, 
and  then  continue  as  above. 


228 

To  the  solutions  in  the  Erlenmeyer  flasks  25  cubic  centi- 
meters of  concentrated  sulphuric  acid  are  added,  and  3  or  4 
rods  of  pure  zinc,  about  5  millimeters  long  and  6  or  7  milli- 
meters in  diameter  are  suspended  in  the  liquid  by  means  of  a 
platinum  wire  attached  to  the  loop  of  a  porcelain  crucible  lid, 
which  is  inverted  over  the  mouth  of  the  flask.  The  liquid  is 
then  gently  boiled  for  30  or  40  minutes.  Then,  without  in- 
terrupting the  boiling,  a  rapid  current  of  CO2  is  introduced 
tinder  the  cover.  The  flask  is  now  rapidly  cooled,  the  zinc 
washed  with  a  jet  of  water  and  removed,  and  the  solution 
titrated  with  permanganate,  while  the  current  of  CO2  is  still 
being  passed  in.  The  difference  between  the  permanganate 
used  in  this  case  and  that  required  for  the  iron  alone,  repre- 
sents the  amount  corresponding  to  the  titanic  acid.  The  fac- 
tor for  metallic  iron  divided  by  0.7  gives  the  factor  for  titanic 
acid  (TiO2). 

The  most  convenient  strength  for  the  permanganate  solu- 
tion is  one  of  7.9  grams  per  liter,  corresponding  to  about  0.014 
gram  of  metallic  iron. 

In  the  determination  of  iron  by  reduction  with  sulphureted 
hydrogen,  no  effect  is  produced  on  cold  permanganate  solu- 
tion by  the  precipitated  sulphur  present,  but  precipitated  sul- 
phides, such  as  copper  sulphide,  should  be  filtered  off  before 
boiling. 

The  results  of  test  analyses  of  recrystallized  potassium  ti- 
tanofluoride  were  somewhat  low,  but  probably  quite  as  good 
or  better  than  any  gravimetric  method. 

RUBRICATING  OIL. 

A  good  lubricant  should  meet  the  following,  generally  ac- 
cepted requirements : 

1 i )  It  must  be  free  from  corrosive  elements  such  as  acids, 
either  of  mineral,  animal  or  vegetable  origin. 

(2)  It  must  have  body  enough  to  form  and  retain  a  fila- 
ment of  the  lubricant  over  the  lubricated  parts  to  prevent 
direct  contact  of  the  metal. 


229 

(3)  A  minimum  coefficient  of  friction. 

(4)  High  boiling-point  to  insure  the  proper  flash  and  fire 
points. 

(5)  Freedom  from  grit  or  tarry  matter. 

(6)  Must  not  gum,  due  to  presence  of  readily  oxidizable 
oils. 

(7)  Must  not  contain  thickener. 

(8)  Must  have  a  low  volatility  at  comparatively  high  tem- 
peratures. 

(9)  Must  not  become  too  thin  when  heated. 

(10)  Should  not  freeze  or  become  thickened  by  moderately 
low  temperatures. 

To  determine  the  above  qualities  the  following  chemical, 
physical,  and  mechanical  tests  are  applied : 

Chemical  Tests: 

1.  Iodine  Absorption. 

2.  Acidity. 

3.  Color  Reactions. 

4.  Saponification. 

5.  Soap  Test. 

6.  Tarry  Matter  and  Grit. 
Physical  Tests: 

1.  Flash  and  Fire  Tests. 

2.  Viscosity. 

3.  Specific  Gravity. 

4.  Cold  Test. 

5.  Index  of  Refraction. 
Mechanical  Test: 

i.  Coefficient  of  Friction. 

Twenty-five  grams  of  iodine  and  30  grams  of  mercuric 
chloride  are  each  dissolved  in  500  cubic  centimeters  of  95  per 
cent,  alcohol,  uniting  the  two  solutions,  and  allowing  to  stand 
several  hours  before  use.  It  is  then  standardized  by  IO/N 
thiosulphate  sodium  solution.  The  process  of  the  determina- 
tion of  the  iodine  absorption  of  an  oil  is  as  follows:  One- 
tenth  to  0.5  gram  of  the  fat  or  oil  is  dissolved  in  10  cubic 


230 

centimeters  of  purest  chloroform  in  a  well-stoppered  flask,  and 
20  cubic  centimeters  of  the  iodine  solution  added.  The 
amount  must  be  finally  regulated  so  that  after  not  less  than 
two  hours  digestion  the  mixture  possesses  a  dark  brown  tint; 
under  any  circumstances  it  is  necessary  to  have  a  considerable 
excess  of  iodine  (at  least  double  the  amount  absorbed  ought  to 
be  present),  and  the  digestion  should  be  from  6  to  8  hours. 
Some  potassium  iodide  solution  is  then  added,  and  the  whole 
diluted  with  150  cubic  centimeters  of  water,  and  IO/N  thio- 
sulphate  solution  delivered  in  until  the  color  is  nearly  dis- 
charged. Starch  is  then  added,  and  the  titration  finished  in 
the  usual  way. 

Acidity:  (a)  Fatty  Acids  in  Compounded  Oils. — Dissolve 
10  grams  of  the  oil  in  50  cubic  centimeters  of  absolute  alcohol 
and  warm,  add  a  drop  of  phenolphthalein  and  titrate  with 
N/5O  soda  solution  until  red  appears.  Calculate  Mg.  NaOH 
required  to  neutralize  I  gram  of  oil. 

(&)  Free  Acid  in  Mineral  Oil. — In  a  separatory  funnel 
shake  25  cubic  centimeters  of  the  oil  with  50  cubic  centi- 
meters of  hot  water,  to  which  a  drop  of  methyl  orange  has 
been  added.  The  water  must  not  turn  red. 

Color  Reaction:  Heidenreich's  test  is  as  follows :  A  clear 
glass  plate  is  placed  over  a  piece  of  white  paper;  10  drops  of 
the  oil  under  examination  are  placed  thereon,  and  I  drop  of 
concentrated  sulphuric  acid  is  added. 

The  color  produced  when  the  acid  comes  in  contact  with 
the  oil  is  noticed  as  well  as  the  color  produced  when  the  two 
are  stirred  with  a  glass  rod.  Many  oils  give  off  characteristic 
odors  during  the  reaction,  especially  neatsfoot  oil,  whale  oil, 
and  menhaden  oil. 

Massie's  test  is  thus  performed : 

Nitric  acid  of  1.40  specific  gravity,  free  from  nitrous  acid 
is  mixed  in  a  test-tube  with  y$  its  volume  of  the  oil,  and  the 
whole  agitated  for  2  minutes. 

The  color  of  the  oil  after  separation  from  the  acid  is  the 
indication. 

In  mixture  of  oils,  the  characteristic  colors  produced,  by 


231 


either  Heindenreich's  or  Massie's  test  are  often  clouded,  and 
in  many  instances  no  inference  can  be  drawn,  yet  with  single 
oils  the  reactions  are  often  distinctive  and  sufficiently  strong 
to  give  confirmatory  results. 

In  cod  liver  oil,  or  w^hale  oil,  when  mixed  with  mineral  or 
even  vegetable  oil,  the  characteristic  brilliant  violet  color  pro- 
duced with  sulphuric  acid  cannot  be  mistaken.  This  color, 
due  to  the  presence  of  cholic  acid,  is  found  in  most  of  the  fish 
oils,  but  is  much  more  pronounced  in  cod  liver  oil. 


Heidenreich's  Test 

Massie's  Test 

Lard  Oil 

Yellow 

Brown 

Yellow 

Tallow  Oil 

Yellow 

Orange 

Colorless 

Neatsfoot  Oil 

Yellowish 

Red-brown 

Red 

Oleo  Oil                   Colorless 

Orange 

Pink 

Elain  Oil 

Light  green  turn- 

Brown 

Orange  Red 

ing  to  brown 

Sperm  Oil 

Brown  with  pur- 

Reddish brown 

Red 

ple  streaks 

Whale  Oil 

Red-violet 

Brown 

Dark  red 

Dog-fish  Oil 
Cod  liver  Oil 

Violet 
Red-violet 

Dark  Brown 
Dark  Brown 

Orange 
Orange-red 

Crude  Cottonseed 

Brilliant  red 

Brown 

Brown 

Ref'd  Cottonseed 

Reddish  brown 

Red 

Orange-  red 

Rape  Oil 

Yellow-brown 

Brown 

Orange 

Castor  Oil 

Light    yellow  to 

Pale  brown 

Orange 

brown 

Olive  Oil 

Light  green 

Greenish  to  light 

Yellow  to  green- 

brown 

ish 

Rosin 

Brown 

Brown 

Orange 

Earth  Nut  Oil 

Yellow  to  Orange 

Greenish 

Reddish 

Saponification:  (a)  Separation  of  the  Mineral  Oil. — Ten 
grams  of  the  oil  are  weighed  in  a  dry  weighed  beaker  (250 
cubic  centimeters),  and  to  it  are  added  75  cubic  centimeters 
of  an  alcoholic  solution  of  potash  (60  grams  of  potassium  hy- 
droxide to  1,000  cubic  centimeters  of  95  per  cent,  alcohol), 
and  the  contents  evaporated  until  all  the  alcohol  is  driven  off. 
In  this  process,  if  any  animal  or  vegetable  oil  is  present,  it  is 
formed  into  a  soap  by  the  potash,  while  the  mineral  oil  is  un- 
acted upon.  Water  (75  cubic  centimeters)  is  now  added  and 
the  material  well  stirred  to  insure  complete  solution  of  the 
soap,  and  then  it  is  transferred  to  a  separatory  funnel,  75 


232 

cubic  centimeters  of  sulphuric  ether  added,  corked,  the  liquid 
violently  agitated  and  allowed  to  stand  for  12  hours.  Two 
distinct  liquids  are  now  seen,  the  lower,  the  solution  of  the 
soap,  the  upper  the  ether  solution  (colored,  if  mineral  oil  is 
present,  colorless  if  not).  The  aqueous  solution  is  drawn  off 
in  a  No.  3  beaker,  the  ethereal  solution  remaining  in  the  sep- 
aratory  funnel.  The  former  is  placed  on  a  water  bath,  heated 
for  y2  .hour,  and  until  all  traces  of  ether  (which  is  absorbed 
by  the  water  in  a  very  small  amount)  is  gone.  The  solution 
is  allowed  to  cool,  diluted  somewhat  with  water,  and  made 
acid  with  dilute  sulphuric  acid.  Any  animal  or  vegetable  oil 
present  will  be  indicated  by  a  rise  of  the  fatty  acids  to  the 
surface  of  the  liquid.  (In  this  reaction  the  sulphuric  acid 
decomposes  the  soap,  uniting  with  the  potash  to  form  sulphate 
of  potash  and  liberating  the  fatty  acids  of  the  oil.) 

If  it  is  desired  to  weigh  the  fatty  acids,  proceed  as  follows : 

Weigh  carefully  about  5  grams  of  pure  white  beeswax, 
place  it  in  the  beaker  upon  the  surface  of  the  oil  and  water, 
and  bring  the  contents  nearly  to  boiling;  the  melted  wax  and 
fatty  acids  unite;  allow  to  cool,  remove  the  wax,  wash  with 
water,  dry  between  folds  of  filter  paper,  and  weigh.  The  in- 
crease in  weight  of  the  wax  over  its  original  weight  gives  the 
weight  of  the  fatty  acids  of  the  animal  or  vegetable  oil  in  the 
lubricating  oil. 

(b)  Saponification  Value. — This  is  expressed  by  the  number 
of  milligrams  of  potassium  hydrate  necessary  to  saponify  I 
gram  of  the  oil.  From  2.5  to  10  grams  of  the  oil,  according 
to  the  percentage  of  saponifiable  matter  supposed  to  be  pres- 
ent, are  boiled  with  25  cubic  centimeters  of  N/2  alcoholic 
potash  in  a  200  cubic  centimeter  Jena  Erlenmeyer  flask.  A 
reflux  condenser  is  used,  and  the  boiling  may  require  from  5 
to  8  hours.  The  excess  of  alkali  is  titrated  with  N/2  HC1, 
using  phenolphthalein.  The  strength  of  the  N/2  KOH  is  de- 
termined by  boiling  25  cubic  centimeters  in  similar  flasks 
alongside  of  those  in  which  the  oil  is  treated  and  for  the  same 
length  of  time. 

Tarry  Matter  and  Grit. — Shake  10  cubic  centimeters  of  the 


233 

oil  with  90  cubic  centimeters  of  petroleum  ether  in  a  test 
tube,  holding  125  cubic  centimeters.  No  deposit  should  ap- 
pear after  standing  for  i  hour. 

Flash  and  Fire  Test. — In  a  porcelain  evaporating  dish  filled 
with  sand,  place  a  platinum  crucible,  suspend  a  thermometer 
reading  at  least  600°  F.  from  a  support  directly  above  the 
crucible  so  that  the  mercury  bulb  will  reach  to  about  the 
middle  of  the  crucible,  care  being  taken  not  to  touch  the 
sides.  Fill  the  crucible  with  oil,  completely  covering  the  bulb 
of  the  thermometer  but  allowing  room  for  the  oil  to  expand 
without  overflowing  on  heating.  Adjust  the  flame  so  that  the 
temperature  of  the  liquid  in  the  dish  rises  at  the  rate  required 
for  the  liquid  being  tested,  and  when  the  temperature  reaches 
a  desired  point,  apply  the  test  flame  by  passing  it  slowly,  en- 
tirely across  the  dish,  about  a  half  inch  above  the  level  of  the 
liquid  and  just  in  front  of  the  thermometer.  Allow  the  liquid 
to  rise  in  temperature  until  another  testing  point  is  reached 
and  then  apply  the  test  flame  again  in  the  same  manner.  Pro- 
ceed in  this  way  until  the  vapor  from  the  liquid  above  it  ignites 
with  a  slight  flash.  The  temperature  shown  by  the  thermom- 
eter when  this  is  the  case  is  the  flashing  point  of  the  liquid. 
Continue  the  heating  and  testing  in  the  same  manner  until  a 
point  is  reached  where  the  liquid  takes  fire.  The  reading  of 
the  thermometer  when  this  is  the  case  is  the  burning  point  of 
the  liquid. 

The  test  flame  can  best  be  adjusted  by  using  a  jeweler's 
blowpipe  and  allowing  enough  gas  to  flow  to  produce  a  flame 
of  2  to  3  millimeters  long. 

Viscosity. — The  viscosity  is  generally  determined  by  the 
rate  of  flow  at  a  specified  temperature  through  an  opening  of 
accurate  standard  size.  It  is  recorded  in  seconds  for  a  speci- 
fied temperature  and  volume. 

By  comparison  with  standards  an  oil  may  be  rated  as  to  its 
viscosity  thus  giving  one  of  the  values  required  for  a  lubri- 
cant. Engler's  apparatus — probably  the  first  used  for  this 
purpose — is  made  of  metal  (copper).  This  instrument  is  the 
standard  for  determining  the  viscosity  of  oil  in  Germany,  and 


234 

is  also  a  standard  in  this  country.  It  is  recommended  by  the 
United  States  Bureau  of  Standards  for  use  unless  another 
form  of  viscosimeter  is  called  for  in  the  specification. 

In  using  this  instrument,  the  viscosity  of  an  oil  is  stated  in 
seconds  required  for  200  cubic  centimeters  of  the  oil  to  run 
into  the  flask.  Two  hundred  and  forty  cubic  centimeters  of 
the  oil  being  placed  in  the  viscosimeter,  water  usually  requir- 
ing from  50  to  53  seconds  at  20°  C.  Heat  can  be  applied  to 
the  water  bath,  the  viscosity  being  determined  at  any  tem- 
perature up  to  1 00°  C.  Higher  temperatures  to  360°  C.  can 
be  secured  by  filling  the  outer  vessel  with  paraffine  instead  of 
water.  Engler  recommends  that  all  viscosities  be  compared 
with  water  thus :  If  water  requires  52  seconds  for  delivery  of 
200  cubic  centimeters  into  the  receiving  flask,  and  the  same 
amount  of  the  oil  under  examination  requires  130  seconds, 

the  ratio  is  determined  by   •    -  =   2.50,  the  oil  thus  having 

a  viscosity  of  2.5  times  that  of  water. 

The  American  Society  for  Testing  Materials,  Report  of 
Committee  D-2,  state  as  follows : 

In  case  it  is  desired  to  correct  for  specific  gravity  of  the  oil, 
the  following  formula  which  gives  the  results  in  specific  vis- 
cosity can  be  used : 

time  of  efflux  of  oil 
Sp.  viscosity  ==  Sp.  grav.  X  timeofeffluxofwater  >-   7-32. 

If  it  is  necessary  to  use  a  quantity  of  oil  less  than  240  cubic 
centimeters,  the  following  quantities  can  be  employed  and 
multiplied  by  the  corresponding  factor: 

Amount  of  oil  put  in,  cc. 45        50        60         120 

Amount  of  oil  run  out,  cc. 25         40         50         100 

Factor  to  change  to  200  cc.  run 

out  and  240  cc.  put  in 5.55     3.62     2.79       1.65 

The  Committee  recommends  the  use  of  the  Saybold  vis- 
cosimeter. In  this  country  it  is  the  most  widely  used  stand- 
ard and  has  the  advantage  that  small  samples  of  125  cubic 
centimeters  are  sufficient  for  the  test.  This  instrument  is 
shown  in  Fig.  58.  The  tests  are  carried  out  in  practically  the 


235 


same  way  as  in  the  Engler,  only  that  a  flask  graduated  to  60 
cubic  centimeters  is  used  for  the  receiver,  and  the  seconds  re- 
quired for  the  oil  to  fill  the  flask  to  the  60  cubic  centimeter 
mark  indicate  the  viscosity. 


FIG.  58. 


Specific  Gravity.— -Lubricating  oils  are  practically  always 
reported  in  degrees  Baume.  It  is,  therefore,  sufficient  to  read 
the  gravity  by  means  of  a  hydrometer,  correcting  for  tempera- 
ture. If  the  oil  is  too  thick  to  float  the  hydrometer,  heat  to 
90°  or  1 00°  F.  The  following  table  can  be  used  for  tempera- 
ture corrections : 


r-^00*  ON  O   —•   cs*  ro  -^  LOO  t^-00*   ON  o'   M   cs   ro  TT  Tf  LOO   t^-X   ON  O*  HI   ^  co-^f 
,_    w    „    cs    CS    CM    CM    CS    CM    CM    CM    CM    CS    CO  CO  CO  ro  CO  CO  CO  CO  rO  tO  CO  •*  >q-  Tf  -3-  ^3- 


00  00  00  00  f^ 


•H  M  O  O  ON  ON  ON  ONOO  OO 


o  t-  r-o  v  v  \  10  u  •«*•  TJ-  ^t-  •*  ro  to 

00   (^  O   *-<   fi  ^O  ^J"  LO^O   r-^-OO   O\  O\  O   •— 
r-c    «    01    CS    M    CS    P)    M    CM    <N    CM    <N    <N    l»,C«5 


oo'   ON  O   H!  cs   co  TJ-  10^0  rix   ON  O   HI'  cs   co  co  tf  iCvO   r^oo   ONO   1-1   cs   to  T  LO  ,C    r^ 
i-.   M  cs   CS   cs   cs   cs   CS   CS   CM   CM   CM   rOrOrOrorOror^r^cOrOrOT-^-Tj-^-Tj-Tr-^-Tr 


vq  \o  up  10  •*  ri-  •*  •*  ro  co  M  N  N  ej  M  —  q  q  q  q  q\  CTNOO  oq  oc  oo  r>.  r>.  t 
00  CT\  6  M  pi  ro  TJ-  i/xo  r^-od  ON  O  -  '  ' 

w   M   <N   CS   N   M   N   N   CS   CN   CM   CM   rOrO 


00*  ON  O  M  cs  rO  ^}-  LOO*  r^-OO  ON  o   M   CM   ro  TJ-  LOO)   r^-OO*   O^  O   *H   CM   ro  rO  •**"  to^O*  r^. 

w  X    CS  CM  CM  CM    CS    CM    CS  CM    CM  CM    cOrOrOt^cO  rO  CO  CO  CO  CO'J-Tf<a-Tj-Tr-^-Tj-'3-Tj- 

oo'  oV  O  i-i  cs'  co  TJ-  LOO  r^oc  ON  O  *-"  cs'  c^  ^  LOO'  t^-oo'  ON  O  *-.  fvj  ro  "^  LOO  r^oo 

M  M    CM  CM  CM  CS    CS    CS    CS  CM    CM  CM    COCOCOrOCOcOcOcOCOcO^"1^<^^*^'TfTj-Tf1^- 

OO*  ONO  >-!  <**  rOTfLOO*  t^-CO  ON  O*  •—'  CM   ro  T^-  LOO'  r^-OC   ^  O   ^   cs"  ro  -^  LOO*  t^  00* 


O   O   ON  ON  ON  ONOO  ,xi  00  OO  00  OO 


ON  O  «  CM'  ro  rf  lovd  vO  r^-oc  cf\  O  «'  CM'  rO  rt-  tO^O  l^-oo'  ON  O  -'  CM'  rO  -<j-  lOsd  t^-cri 
w    CM    CM    CM    CM    CM    CM    CS    CS    CS    CM    CS    COt^COrOrOrOCOrOrOrOTT-<3--^-T}-->rTr-^-i3--^- 


cscMMi-iMi-iHMp-i)-iqqqqqqONONq^qNON  ONOC  oq  oq  oq  oq  oq  r^.  r^.  t--. 
ON  o'  >-<  cs'  ro  TJ-  LO\O  t^-oo'  ON  o'  M  cs"  ro  -4-  TJ-  ir>\6  t-^-od  <?•  6  >-  cs  ro  -^-  LOO'  i^-oo' 

1-1  CM  CS  CM  CM  CM  CS  CS  CS  CM  CM  rOCOrOrOrOCOCOfOrOrOCO-S-Tj-Tj-Ti-Tj-Ttf-Tr^-Tj- 


O\  O    ^    CM    rO  "^"  *OO'   t-^00*   ON  O    HI   CM    ro  -^  LOO'   r^-GO    O\  O   HI   CM*   CO  ^  LOO*  r^-OO    ON 

ON  o"  HI   (N   ro  ^f  LOO"  r-*-Oo"  ON  O*  •-.   cs'  CO  ^t"  LO\O  t^-00   ON  O*  ^   CM"  rO  rf  LOO  r~--00'  ON 
HI    CM    CS    CM    CMM    CM    CS    CM    CS    CM    P>  IO  fO  W  tO  W  ««*>«*>  tO  *•*  <T  ^r1"*-^  **r*  •«* 


oq  c 

(>0    HI    CS 


ONONONONONONONONONONONONON  ONOO  OO  00  00  00  00  00  00  OO  00  00  00  CO  OO  00  OO  OO 

' 


q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q 


<  O  •*•>   O   HI   CM   CO  TT  LOOI  t^OO   ON  O   M   CM   co  •*  LO>O  t^OO   O^  O   M  cs   rO  TT  LOO   r^oC   ON  O 

<  *"•  CU   ^   ^   N   N   ^   ^   ^   ^   ^   ^   rorOrOcOrOcOrOcOcocO^'^'^-Tf^-'^-^-Tj-Tj-T^-LO 
"^ 


237 

Cold  Test. — Twenty  cubic  centimeters  of  the  oil  are  trans- 
ferred to  a  narrow  bottle  or  test  tube,  stoppered  with  a  rubber 
stopper,  through  which  is  inserted  a  thermometer,  the  bulb  of 
which  remains  an  inch  or  more  into  the  oil. 

The  bottle  is  placed  in  a  mixture  of  ice  and  salt,  or  other 
freezing  compound,  and  retained  there  until  the  oil  becomes 
solid.  It  is  then  removed  and  allowed  to  warm  until  the  con- 
tents become  somewhat  thinner  in  consistency.  The  bottle  is 
inclined  from  side  to  side  until  the  oil  begins  to  flow,  when 
the  temperature  is  taken. 

At  this  particular  temperature  the  oil  is  neither  at  its  nor- 
mal fluidity,  nor  is  it  solid,  and  while  this  method  does  not 
correctly  indicate  the  exact  temperature  of  the  solidify  ing- 
point,  it  does  show  the  point  at  which  the  oil  ceases  to  flow 
readily,  the  important  one  to  the  oil  inspector. 

These  methods  are  in  part  taken  from  Stillman's  "Analysis 
of  Lubricating  Oil." 

SOLDER. 
Tin  and  Antimony  Determination. 

Tin  Determination. — Dissolve  0.5  gram  of  very  finely  di- 
vided sample  (best  done  with  hacksaw)  in  50  cubic  centi- 
meters of  concentrated  hydrochloric  acid  till  action  ceases, 
passing  a  stream  of  CO2  gas,  during  the  whole  operation  to 
prevent  oxidation,  cool,  still,  passing  CO2.  Add  starch  paste 
and  titrate  with  IO/N  iodine  solution.  Cubic  centimeters  used 
x  1.18  =  per  cent.  tin. 

Antimony  Determination. — Dissolve  0.5  gram  metal  in  hy- 
drochloric acid  (as  in  tin  determination,  except  not  using  CO2 
gas).  After  action  ceases,  add  small  quantities  of  iodine 
crystals.  Boil  off  excess  iodine,  cool,  dilute  to  150  cubic 
centimeters  (put  in  500  cubic  centimeter  flask),  add  50  cubic 
centimeters  of  Rochelle  salt  solution  (10  —  20  grams  salt  in 
the  50  cubic  centimeters  of  water,  keep  cold,  and  nearly  neu- 
tralize with  sodium  bicarbonate,  then  completely  neutralize 
with  sodium  hydrate,  keep  cold  (using  litmus  paper).  Add 
16 


238 

quickly  concentrated  sodium  bicarbonate  solution  till  milky. 
Add  starch  paste  and  titrate  with  lo/N  iodine  solution.  Cubic 
centimeters  used  x  1.2  =  per  cent,  antimony. 

Lead  is  seldom  determined  but  instead  is  taken  by  differ- 
ence. It  may,  however,  be  determined  by  the  method  described 
under  Babbitt. 

One-tenth  normal  iodine  solution:  6.35  grams  iodine  and  9 
grams  of  potassium  iodine  to  500  cubic  centimeters  of  water. 

HARD  L,E)AD  AND  BABBITT. 

To  determine  antimony  in  hard  lead,  the  method  for  Babbitt 
metal  can  be  used. 

To  Determine  Copper  and  Lead. — Five-tenth  gram  of  the 
finely  divided  sample  in  nitric  acid  adding  0.5  gram  of  chem- 
ically pure  copper  (to  avoid  sponging  of  the  lead  on  the 
cathods)  evaporate  until  almost  dry  and  redissolve  in  88 
cubic  centimeters  of  nitric  acid  with  50  cubic  centimeters  of 
distilled  water,  filter,  wash  well  with  water  and  electrolyze 
(see  Copper  Alloys),  deduct  the  0.5  gram  C  added  from  your 
weight  of  the  cathods,  the  remainder  in  the  C  in  the  Babbitt. 
The  increase  of  the  weight  of  the  annode  multiplied  by  0.868 
x  2  x  100  gives  the  lead  as  metallic  lead. 

COPPER  AU.OYS. 

Weigh  out  I  gram  of  the  clean  borings  into  a  250  cubic 
centimeter  beaker,  dissolve  in  20  cubic  centimeters  of  diluted 
nitric  acid  and  evaporate  to  dryness. 

Redissolve  with  10  cubic  centimeters  concentrated  nitric 
acid  and  40  cubic  centimeters  of  water  and  filter  off  the  oxide 
of  tin,  running  the  filtrate  into  a  250  cubic  centimeter  beaker, 
wash  well  with  distilled  water  and  fill  the  beaker  to  within  l/2 
inch  of  the  top. 

The  solution  is  then  electrolyzed  by  placing  two  platinum 
electrodes  previously  weighed  and  connected  with  a  4-volt 
direct  current  (storage  battery  or  Edison  Laland  cells  are 
best  fitted  for  the  purpose)  at  a  rate  of  about  y2  ampere  per 


239 

hour.  After  about  10  to  12  hours  all  of  the  copper  will  be 
deposited  on  the  negative  electrode  as  metallic  copper,  the 
lead  on  the  positive  electrode  as.  black  peroxide.  The  elec- 
trolyte is  then  quickly  removed  by  lowering  the  beaker  and 
washed  by  replacing  it  with  a  beaker  of  distilled  water  and 
then  a  beaker  of  alcohol.  The  electrodes  are  then  dried  and 
weighed.  The  increase  gives  the  per  cent,  of  copper  direct; 
the  lead  is  calculated  by  multiplying  the  weight  of  the  oxide 
with  0.868. 

The  oxide  of  tin  is  burned  off  and  weighed.  The  weights 
multiplied  by  0.7881  gives  the  per  cent,  of  metallic  tin. 

To  the  electrolyte  from  the  electrolysis,  ammonia  is  added 
until  decidedly  ammoniacal,  boil  off  excess  and  filter  off  any 
iron  hydroxide  present,  burn  off  and  weigh.  If  zinc  is  present, 
precipitate  with  hydrogen  sulphide,  filter  and  burn  to  zinc 
oxide,  weigh  and  calculate  to  metallic  zinc. 

In  alloys  containing  nickel,  the  electrolyte  after  the  copper 
has  been  deposited  and  weighed  is  made  alkaline  with  an  ex- 
cess of  ammonia  and  the  electrode  coated  with  the  copper  re- 
placed and  a  current  of  6  volts  passed  through  it  to  deposit 
the  nickel  as  metallic  nickel.  It  is  advisable  to  use  the  copper 
plated  cathod,  since  the  nickel  when  deposited  direct  on  the 
platinum  is  hard  to  remove. 

LIME. 

In  works  practice  the  analysis  is  confined  to  determine  the 
quality  of  the  lime  as  a  binder  for  mortar  and  as  an  alkaline 
for  setting  free  ammonia  from  its  fixed  salts. 

A  high  percentage  of  calcium  oxide  is  most  desirable  and 
the  determination  of  CaO  therefore  suffices  for  most  purposes. 

In  selecting  the  sample,  about  a  bucket  full  of  lumps  are 
quickly  broken  up  into  pieces  the  size  of  a  pea,  and  quartered 
down  until  one-quarter  fills  approximately  a  pint  bottle ;  pre- 
caution should  be  taken  to  prevent  the  sample  from  absorbing 
moisture  or  CO2  from  the  air. 

One  hundred  grams  of  this  sample  are  weighed  into  a  i 


240 


liter  flask.     The  sample  is  next  slaked  and  the  flask  filled  to 
the  mark  with  water  and  well  shaken. 

One  hundred  cubic  centimeters  of  this  milk  of  lime,  with- 
out letting  it  settle  are  transferred  to  another  liter  flask  again 
filled  to  the  mark  and  well  shaken.  Fifty  cubic  centimeters 
of  this  solution  are  transferred  to  an  Erlenmeyer  flask  of  250 
cubic  centimeters  capacity,  adding  a  few  drops  of  phenace- 
tolin  as  an  indicator,  and  titrated  with  normal  hydrochloric 
acid  solution  until  the  solution  becomes  a  faint  pink.  The 
caustic  lime  is  calculated  from  the  number  of  cubic  centi- 
meters of  HC1  neutralized. 


FIG.  59. 


The  titration  is  then  continued  until  the  solution  changes 
first  to  red  and  finally  to  yellow,  the  second  titration  giving  the 


241 


carbonate  of  lime.  It  is  sometimes  desirable  to  determine  the 
unburned  lime  by  determining  the  CO2  and  calculating  it 
therefrom.  It  can  best  be  done  by  means  of  an  alkalimeter. 
See  Fig.  59. 


FIG.   60. 

The  latter  consists  of  a  glass  vessel  having  a  glass  stoppered 
opening  at  the  side  through  which  the  sample  is  introduced, 
a  separatory  funnel  with  a  glass  stopper  at  one  side  of  the 
top  and  a  gas  scrubbing  tube  at  the  other. 

To  use  the  apparatus  the  gas  scrubbing  tube  is  first  filled  y$ 
full  with  concentrated  sulphuric  acid.  The  separatory  fun- 


242 


nel  is  then  filled  with  diluted  HC1  (y2  acid,  y2  water)  and  the 
apparatus  weighed. 

Then  approximately  5  grams  of  the  powdered  sample  are  in- 
troduced through  the  glass  stoppered  opening  and  the  whole 
is  again  weighed.  The  acid  in  the  separating  funnel  is  next 


FIG.  61. 

run  into  the  vessel  through  the  stop-cock,  and  after  the  reac- 
tion ceases,  the  flask  is  slightly  warmed.  After  cooling  it  is 
again  weighed.  The  difference  between  the  second  and  third 
weights  represents  the  CO2  driven  off.  By  dividing  the  differ- 
ence between  the  first  and  second  weight  (the  weight  of  the 


243 

sample),  into  the  third  and  mutliplied  by  100,  the  percentage  of 
CO,  is  found  and  the  percentage  of  calcium  carbonate  can  be 
calculated  therefrom. 

MAGNESIUM. 

For  the  determination  of  magnesium  follow  scheme  under 
Refractories  or  Water  Analysis. 

Efficiency  Test.  For  Use  in  Ammonia  Still. — Five  grams 
of  the  sample  are  placed  in  a  Kjeldahl  flask  and  slaked.  The 
flask  is  next  connected  with  the  condenser  of  an  ammonia  dis- 
tilling apparatus. 

Through  a  separatory  funnel  are  then  added  10  grams  of 
ammonium  sulphate  previously  dissolved  in  water.  The  am- 
monia liberated  on  boiling  is  absorbed  in  a  beaker  containing 
standard  sulphuric  acid.  The  operation  is  the  same  as  in  the 
determination  of  ammonia  in  ammoniacal  liquors. 

From  the  ammonia  thus  determined,  the  efficiency  of  the 
lime  can  be  determined  as  follows : 

a  =  NH3  found 

b  =  CaO  used 

f*  X  56\ 

\      34     ' 

b 

CO2  IN  AIR. 

For  the  determination  of  CO2  in  air,  there  are  two  appara- 
tuses generally  used,  the  one  is  Haldane's  (Fig.  60)  and  the 
other  Patterson's  (Fig.  61).  These  apparatuses  differ  from 
the  Orsat  apparatus  that  the  gas  volume  can  be  read  as  close 
as  o.ooi  of  a  cubic  centimeter  and  CO2  can,  therefore,  be 
determined  in  o.oooi  by  volume. 

CEMENT. 

STANDARD  SPECIFICATIONS  FOR  CEMENT,  AS  PUBLISHED  BY 

THE  AMERICAN  SOCIETY  FOR  TESTING  MATERIALS. 

Adopted,  1904;  Revised,  1908,  1909. 

GENERAL  OBSERVATIONS. 
i.  These  remarks  have  been  prepared  with  a  view  of  point- 


244 

ing  out  the  pertinent  features  of  the  various  requirements  and 
the  precautions  to  be  observed  in  the  interpretation  of  the 
results  of  the  tests. 

2.  The  Committee  would   suggest  that  the  acceptance   or 
rejection  under  these  specifications  be  based  on  tests  made  by 
an  experienced  person  having  the  proper  means  for  making 
the  tests. 

SPECIFIC  GRAVITY. 

3.  Specific  gravity  is  useful  in  detecting  adulteration.     The 
results  of  tests  of  specific  gravity  are  not  necessarily  conclu- 
sive as  an  indication  of  the  quality  of  a  cement,  but  when  in 
combination  with  the  results  of  other  tests  may  afford  valu- 
able indications. 

FINENESS. 

4.  The  sieves  should  be  kept  thoroughly  dry. 

TIME  OF  SETTING. 

5.  Great  care  should  be  exercised  to  maintain  the  test  pieces 
under  as  uniform  conditions  as  possible.    A  sudden  change  or 
wide  range  of  temperature  in  the  room  in  which  the  tests  are 
made,  a  very  dry  or  humid  atmosphere,  and  other  irregulari- 
ties vitally  affect  the  rate  of  setting. 

•  CONSTANCY  OF  VOLUME. 

6.  The  tests  for  constancy  of  volume  are  divided  into  two 
classes,  the  first  normal,  the  second  accelerated.     The  latter 
should  be  regarded  as  a  precautionary  test  only,  and  not  in- 
fallible.   So  many  conditions  enter  into  the  making  and  inter- 
preting of  it  that  it  should  be  used  with  extreme  care. 

7.  In  making  the  pats  the  greatest  care  should  be  exercised 
to  avoid  initial  strains  due  to  molding  or  to  too  rapid  drying- 
out  during  the  first  24  hours.     The  pats  should  be  preserved 
under  the  most  uniform  conditions  possible,  and  rapid  changes 
of  temperature  should  be  avoided. 

8.  The  failure  to  meet  the  requirements  of  the  accelerated 


245 

tests  need  not  be  sufficient  cause  for  rejection.  The  cement  may, 
however,  be  held  for  28  days,  and  a  retest  made  at  the  end  of 
that  period,  using  a  new  sample.  Failure  to  meet  the  require- 
ments at  this  time  should  be  considered  sufficient  cause  for 
rejection,  although  in  the  present  state  of  our  knowledge  it 
cannot  be  said  that  such  failure  necessarily  indicates  unsound- 
ness,  nor  can  the  cement  be  considered  entirely  satisfactory 
simply  because  it  passes  the  tests. 

SPECIFICATIONS. 
General  Conditions. 

1.  All  cement  shall  be  inspected. 

2.  Cement  may  be  inspected  either  at  the  place  of  manu- 
facture or  on  the  work. 

3.  In  order  to  allow  ample  time  for  inspecting  and  testing, 
the  cement  should  be  stored  in  a  suitable  weather-tight  build- 
ing having  the   floor   properly   blocked   or   raised   from   the 
ground. 

4.  The  cement  shall  be  stored  in  such  a  manner  as  to  permit 
easy  access  for  proper  inspection  and  identification  of  each 
shipment. 

5.  Every  facility  shall  be  provided  by  the  Contractor  and  a 
period  of  at  least  12  days  allowed  for  the  inspection  and  nec- 
essary tests. 

6.  Cement  shall  be  delivered  in  suitable  packages  with  the 
brand  and  name  of  manufacturer  plainly  marked  thereon. 

7.  A  bag  of  cement  shall  contain  94  pounds  of  cement  net. 
Each  barrel  of  Portland  cement  shall  contain  four  bags,  and 
each  barrel  of  natural  cement  shall  contain  three  bags  of  the 
above  net  weight. 

8.  Cement  failing  to  meet  the  7-day  requirements  may  be 
held  awaiting  the  results  of  the  28-day  tests  before  rejection. 

9.  All  tests  shall  be  made  in  accordance  with  the  methods 
proposed  by  the  Committee  on  Uniform  Tests  of  Cement  of 
the  American  Society  of  Civil  Engineers,  presented  to  the  So- 
ciety January  21,  1903,  and  amended  January  20,  1904,  and 


246 

January   15,   1908,  with  all   subsequent  amendments  thereto. 
(See  addendum  to  these  specifications.) 

10.  The  acceptance  or  rejection  shall  be  based  on  the  fol- 
lowing requirements: 

Natural  Cement. 

11.  Definition. — This  term  shall  be  applied  to  the  finely  pul- 
verized product  resulting  from  the  calcination  of  an  argillace- 
ous limestone  at  a  temperature  only  sufficient  to  drive  off  the 
carbonic  acid  gas. 

FINENESS. 

12.  It  shall  leave  by  weight  a  residue  of  not  more  than  10 
per  cent,  on  the  No.  100,  and  30  per  cent,  on  the  No.  200  sieve. 

TIME  oi?  SETTING. 

13.  It  shall  not  develop  initial  set  in  less  than  10  minutes; 
and  shall  not  develop  hard  set  in  less  than  30  minutes,  or  in 
more  than  3  hours. 

TENSILE  STRENGTH. 

14.  The  minimum  requirements  for  tensile  strength  for  bri- 
quets i  square  inch  in  cross  section  shall  be  as  follows,  and 
the  cement  shall  show  no  retrogression  in  strength  within  the 
periods  specified : 

Neat  Cement. 

Age  Strength 

24  hours  in  moist  air 75  pounds 

7  days  (i  day  in  moist  air,    6  days  in  water)  150  pounds 

28  days  (i  day  in  moist  air,  27  days  in  water)  250  pounds 

One  Part  Cement,  Three  Parts  Standard  Ottawa  Sand. 

7  days  (i  day  in  moist  air,    6  days  in  water)  50  pounds 

28  days  (i  day  in  moist  air,  27  days  in  water)  125  pounds 

CONSTANCY  OF  VOLUME. 

15.  Pats  of  neat  cement  about  3  inches  in  diameter,  y2  inch 
thick  at  center,  tapering  to  a  thin  edge,  shall  be  kept  in  moist 
air  for  a  period  of  24  hours. 

(a)   A  pat  is  then  kept  in  air  at  normal  temperature. 


247 

(b)  Another  is  kept  in  water  maintained  as  near  70°  F.  as 
practicable. 

1 6.  These  pats  are  observed  at  intervals  for  at  least  28  days, 
and,  to  satisfactorily  pass  the  tests,  shall  remain  firm  and  hard 
and  show  no  signs  of  distortion,  checking,  cracking,  or  disinte- 
grating. 

Portland  Cement. 

17.  Definition. — This  term  is  applied  to  the  finely  pulverized 
product  resulting  from  the  calcination  to  incipient  fusion  of 
an  intimate  mixture  of  properly  proportioned  argillaceous  and 
calcareous  materials,  and  to  which  no  addition  greater  than 
3  per  cent,  has  been  made  subsequent  to  calcination. 

SPECIFIC  GRAVITY. 

1 8.  The  specific  gravity  of  cement  shall  not  be  less  than 
3.10.     Should  the  test  of  cement  as  received  fall  below  this 
requirement,  a  second  test  may  be  made  upon  a  sample  ignited 
at  a  low  red  heat.    The  loss  in  weight  of  the  ignited  cement 
shall  not  exceed  4  per  cent. 

FINENESS. 

19.  It  shall  leave  by  weight  a  residue  of  not  more  than  8 
per  cent,  on  the  No.  100,  and  not  more  than  25  per  cent,  on  the 
No.  200  sieve. 

TIME  OF  SETTING. 

20.  It  shall  not  develop  initial  set  in  less  than  30  minutes; 
and  must  develop  hard  set  in  not  less  than  i  hour,  nor  more 
than  10  hours. 

TENSILE  STRENGTH. 

21.  The  minimum  requirements  for  tensile  strength  for  bri- 
quets I  square  inch  in  cross  section  shall  be  as  follows,  and 
the  cement  shall  show  no  retrogression  in  strength  within  the 
periods  specified: 


248 
Neat  Cement. 

Age  Strength 

24  hours  in  moist  air 175  pounds 

7  days  (i  day  in  moist  air,    6  days  in  water)  500  pounds 

28  days  (i  day  in  moist  air,  27  days  in  water)  600  pounds 

One  Part  Cement,  Three  Parts  Standard  Ottawa  Sand. 

7  days  (i  day  in  moist  air,    6  days  in  water)  200  pounds 

28  days  (i  day  in  moist  air,  27  days  in  water)  275  pounds 

CONSTANCY  OF  VOLUME. 

22.  Pats  of  neat  cement  about  3  inches  in  diameter,  y2  inch 
thick  at  the  center,  and  tapering  to  a  thin  edge,  shall  be  kept 
in  moist  air  for  a  period  of  24  hours. 

(a)  A  pat  is  then  kept  in  air  at  normal  temperature  and  ob- 
served at  intervals  for  at  least  28  days. 

(b)  Another  pat  is  kept  in  water  maintained  as  near  70° 
F.  as  practicable,  and  observed  at  intervals   for  at  least  28 
days. 

(c)  A  third  pat  is  exposed  in  any  convenient  way  in  an 
atmosphere  of  steam,  above  boiling  water,  in  a  loosely  closed 
vessel  for  5  hours. 

23.  These  pats,  to  satisfactorily  pass  the  requirements,  shall 
remain  firm  and  hard,  and  show  no  signs  of  distortion,  check- 
ing, cracking,  or  disintegrating. 

SULPHURIC  ACID  AND  MAGNESIA. 

24.  The  cement  shall  not  contain  more  than  1.75  per  cent, 
of  anhydrous  sulphuric  acid  (SO3),  nor  more  than  4  per  cent, 
of  magnesia  (MgO). 

ADDENDUM. 

METHODS  FOR  TESTING  CEMENT.1 

Recommended  by  the  Special  Committee  on  Uniform  Tests  of  Cement 
of  the  American  Society  of  Civil  Engineers. 

SAMPLING. 

i.  Selection    of    Sample. — The    selection    of    samples    for    testing 
should  be  left  to  the  engineer.    The  number  of  packages  sampled  and 

1  Accompanying  Final  Report  of  Special  Committee  on  Uniform  Tests  of  Cement 
of  the  American  Society  of  Civil  Engineers,  dated  January  17,  1912. 


249 

the  quantity  taken  from  each  package  will  depend  on  the  importance 
of  the  work  and  the  facilities  for  making  the  tests. 

2.  The  samples   should   fairly  represent  the  material.     When  the 
amount  to  be  tested  is  small  it  is  recommended  that  I  barrel  in  10  be 
sampleti ;  when  the  amount  is  large  it  may  be  impracticable  to  take 
samples  from  more  than  I  barrel  in  30  or  50.    When  the  samples  are 
taken  from  bins  at  the  mill  I  for  each  50  to  200  barrels  will  suffice. 

3.  Samples  should  be  passed  through  a  sieve  having  twenty  meshes 
per  linear  inch,  in  order  to  break  up  lumps  and  remove  foreign  mate- 
rial; the  use  of  this  sieve  is  also  effective  to  obtain  a  thorough  mixing 
of  the  samples  when  this  is  desired.    To  determine  the  acceptance  or 
rejection  of  cement  it  is  preferable,  when  time  permits,  to  test  the 
samples  separately.     Tests  to  determine  the  general  characteristics  of 
a  cement,   extending  over  a  long  period   may  be  made  with  mixed 
samples. 

4.  Method   of  Sampling, — Cement   in   barrels   should   be   sampled 
through  a  hole  made  in  the  head,  or  in  one  of  the  staves  midway 
between  the  heads,  by  means  of  an  auger  or  a  sampling  iron  similar  to 
that  used  by  sugar  inspectors;  if  in  bags,  the  sample  should  be  taken 
from  surface  to  center;  cement  in  bins  should  be  sampled  in  such  a 
manner  as  to  represent  fairly  the  contents  of  the  bin.     Sampling  from 
bins  is  not  recommended  if  the  method  of  manufacture  is  such  that 
ingredients  of  any  kind  are  added  to  the  cement  subsequently. 

CHEMICAI,  ANALYSIS. 

5.  Significance. — Chemical  analysis  may  serve  to  detect  adultera- 
tion of  cement  with  inert  material,  such  as  slag  or  ground  limestone, 
if  in  considerable  amount.    It  is  useful  in  determining  whether  certain 
constituents,  such  as  magnesia  and  sulphuric  anhydride,  are  present  in 
inadmissible  proportions. 

6.  The  determination  of  the  principal  constituents  of  cement,  silica, 
alumina,  iron  oxide,  and  lime,  is  not  conclusive  as  an  indication  of 
quality.    Faulty  cement  results  more  frequently  from  imperfect  prepa- 
ration of  the  raw  material  or  defective  burning  than  from  incorrect 
proportions.     Cement   made    from   material    ground   very   finely   and 
thoroughly   burned   may  contain   much   more   lime   than   the   amount 
usually  present,   and   still  be  perfectly  sound.     On  the   other  hand, 
cements  low  in  lime  may,  on  account  of  careless  preparation  of  the  raw 
material,  be  of  dangerous  character.    Furthermore,  the  composition  of 
the  product  may  be  so  greatly  modified  by  the  ash  of  the  fuel  used  in 
burning  as  to  affect  in  a  great  degree  the  significance  of  the  results 
of  analysis. 


25° 

7.  Methods. — The  methods  to  be  followed,  except  for  determining 
the  loss  on  ignition,  should  be  those  proposed  by  the  Committee  on 
Uniformity  in  the  Analysis   of   Materials   for   the   Portland   Cement 
Industry,  reported  in  the  Journal  of  the  Society  for  Chemical  Industry, 
Vol.  21,  p.  12,  1902;  and  published  in  Engineering  News,  Vol.  50,  p.  60, 
1903;  and  in  Engineering  Record,  Vol.  48,  p.  49,  1903,  and  in  addition 
thereto,  the  following : 

(a)  The  insoluble  residue  may  be  determined  as  follows :     To  a 
i -gram  sample  of  the  cement  are  added  30  cubic  centimeters  of  water 
and  10  cubic  centimeters  of  concentrated  hydrochloric  acid,  and  then 
warmed  until  effervescence  ceases,  and  digested  on  a  steam  bath  until 
dissolved.     The  residue  is  filtered,  washed  with  hot  water,   and  the 
filter  paper  and  contents  digested  on  the  steam  bath  in  a  5  per  cent, 
solution  of  sodium  carbonate.     This  residue  is  filtered,  washed  with 
hot  water,  then  with  hot  hydrochloric  acid,  and  finally  with  hot  water, 
and  then  ignited  at  a  red  heat  and  weighed.    The  quantity  so  obtajped 
is  the  insoluble  residue. 

(b)  The   loss   on  ignition   shall   be   determined  in  the   following 
manner:     One-half  gram  of  cement  is  heated  in  a  weighed  platinum 
crucible,  with  cover,  for  5  minutes  with  a  Bunsen  burner  (starting  with 
a  low  flame  and  gradually  increasing  to  its  full  height)  and  then  heated 
for  15  minutes  with  a  blast  lamp;  the  difference  between  the  weight 
after  cooling  and  the  original  weight  is  the  loss   on  ignition.     The 
temperature  should  not  exceed  900°  C.,  or  a  low  red  heat;  the  ignition 
should  preferably  be  made  in  a  muffle. 

SPECIFIC  GRAVITY. 

8.  Significance. — The    specific    gravity    of    cement    is    lowered    by 
adulteration  and  hydration,  but  the  adulteration  must  be  considerable 
to  be  detected  by  tests  of  specific  gravity. 

9.  Inasmuch  as  the  differences  in  specific  gravity  are  usually  very 
small,  great  care  must  be  exercised  in  making  the  determination. 

10.  Apparatus. — The  determination  of   specific  gravity  should  be 
made  with  a  standardized  Le  Chatelier  apparatus.     This  consists  of  a 
flask  (D),  Fig.  62,  of  about  120  cubic  centimeters  capacity,  the  neck 
of  which  is  about  20  centimeters  long;  in  the  middle  of  this  neck  is  a 
bulb   (C),  above  and  below  which  are  two  marks   (F)   and   (£)  ;  the 
volume  between  these  two  marks  is  20  cubic  centimeters.     The  neck 
has  a  diameter  of  about  9  millimeters,  and  is  graduated  into  tenths  of 
cubic  centimeters  above  the  mark  (/•*)• 

11.  Benzine    (62°   Baume  naphtha)   or  kerosene  free  from  water 
should  be  used  in  making  the  determination. 

12.  Method. — The  flask  is  filled  with  either  of  these  liquids  to  the 
lower  mark  (B),  and  64  grams  of  cement,  cooled  to  the  temperature 
of  the  liquid,  is  slowly  introduced  through  the  funnel  (B},  the  stem  of 


251 


which  should  be  long  enough  to  extend  into  the  flask  to  the  top  of  the 
bulb  (Oi  taking  care  that  the  cement  does  not  adhere  to  the  sides 
of  the  flask,  and  that  the  funnel  does  not  touch  the  liquid.  After  all 
the  cement  is  introduced,  the  level  of  the  liquid  will  rise  to  some 
division  of  the  graduated  neck;  this  reading,  plus  20  cubic  centimeters, 
is  the  volume  displaced  by  64  grams  of  the  cement. 


FIG.  62.— Le  Chatelier's  Specific  Gravity  Apparatus. 

\ 
13.  The  specific  gravity  is  then  obtained  from  the  formula, 

Weight  of  cement,  in  grams, 


Specific  gravity  = 


Displaced  volume,  in  cubic  centimeters. 
14.  The  flask,  during  the  operation,  is  kept  immersed  in  water  in  a 
jar  (A),  in  order  to  avoid  variations  in  the  temperature  of  the  liquid 
in  the  flask,  which  should  not  exceed  J4°  C.     The  results  of  repeated 
tests  should  agree  within  o.oi.     The  determination  of  specific  gravity 


252 


should  be  made  on  the  cement  as  received ;  if  it  should  fall  below 
3.10,  a  second  determination  should  be  made  after  igniting  the  sample 
in  a  covered  dish,  preferably  of  platinum,  at  a  low  red  heat  not  exceed- 
ing 900°  C.  The  sample  should  be  heated  for  5  minutes  with  a  Bunsen 
burner  (starting  with  a  low  flame  and  gradually  increasing  to  its  full 
height)  and  then  heated  for  15  minutes  with  a  blast  lamp;  the  ignition 
should  preferably  be  made  in  a  muffle. 

15.  The  apparatus  may  be  cleaned  in  the  following  manner :     The 
flask  is  inverted  and.  shaken  vertically  until  the  liquid  flows  freely,  and 
then  held  in  a  vertical  position  until   empty ;   any  traces   of   cement 
remaining  can  be  removed  by  pouring  into  the  flask  a  small  quantity 
of  clean  liquid  benzine  or  kerosene  and  repeating  the  operation. 

FINENESS. 

16.  Significance. — It  is  generally  accepted  that  the  coarser  particles 
in  cement  are  practically  inert,  and  it  is  only  the  extremely  fine  powder 
that  possesses  cementing  qualities.     The  more  finely  cement  is  pul- 
verized, other  conditions  being  the  same,  the  more  sand  it  will  carry 
and  produce  a  mortar  of  a  given  strength. 

17.  Apparatus. — The  fineness  of  a  sample  of  cement  is  determined 
by  weighing  the  residue  retained  on  certain  sieves.     Those  known  as 
No.  100  and  No.  200,  having  approximately  100  and  200  wires  per  linear 
inch,  respectively,  should  be  used.     They  should  be  8  inches  in  diam- 
eter.    The  frame  should  be  of  brass,  8  inches  in  diameter,  and  the 
sieve  of  brass  wire  cloth  conforming  to  the  following  requirements: 


No.  of  sieve 

Diameter  of  wire, 
inches 

Meshes,  per  linear  inch 

Warp 

Woof 

100 
2OO 

0.0042  to  0.0048 

O.OO2I  to  O.OO23 

95  to  IOI 
192  to  203 

93  to  103 
190  to  205 

The  meshes  in  any  smaller  space,  down  to  0.25  inch,  should  be  pro- 
portional in  number. 

18.  Method. — The  test  should  be  made  with  50  grams  of  cement, 
dried  at  a  temperature  of  100°  C  (212°  F.). 

19.  The  cement  is  placed  on  the  No.  200  sieve,  which,  with  pan  and 
cover  attached,  is  held  in  one  hand  in  a  slightly  inclined  position,  and 
moved  forward  and  backward  about  200  times  per  minute,  at  the  same 
time  striking  the  side  gently,  on  the  up  stroke,  against  the  palm  of  the 
other  hand.    The  operation  is  continued  until  not  more  than  0.05  gram 
will  pass  through  in  I  minute.     The  residue  is  weighed,  then  placed 


253 


on  the  No.  100  sieve,  and  the  operation  repeated.  The  work  may  be 
expedited  by  placing  in  the  sieve  a  few  large  steel  shot,  which  should 
be  removed  before  the  final  I  minute  of  sieving.  The  sieves  should 
be  thoroughly  dry  and  clean. 

NORMAI,  CONSISTENCY. 

20.  Significance. — The  use  of  a  proper  percentage  of  water  in 
making  pastes1  and  mortars  for  the  various  tests  is  exceedingly  impor- 
tant and  affects  vitally  the  results  obtained. 


FIG.  63.— Vicat  Apparatus. 


21.  The  amount  of  water,  expressed  in  percentage  by  weight  of  the 
dry  cement,  required  to  produce  a  paste  of  plasticity  desired,  termed 

1  The  term  "paste"  is  used  in  this  report  to  designate  a  mixture  of  cement  and 
water  and  the  word  "mortar"  to  designate  a  mixture  of  cement,  sand  and  water. 

17 


254 

"normal  consistency,"  should  be  determined  with  the  Vicat  apparatus 
in  the  following  manner: 

22.  Apparatus. — This  consists  of  a  frame   (A},  Fig.  63,  bearing  a 
movable  rod  (B),  weighing  300  grams,  one  end  (C)  being  I  centimeter 
in  diameter  for  a  distance  of  6  centimeters,  the  other  having  a  remov- 
able needle    (D),   I   millimeter  in  diameter,  6  millimeters  long.     The 
rod  is  reversible,  and  can  be  held  in  any  desired  position  by  a  screw 
(B),   and  has  midway  between  the  ends   a  mark    (F)    which  moves 
under  a  scale  (graduated  to  millimeters)   attached  to  the  frame   (A). 
The  paste  is  held  in  a  conical,  hard-rubber  ring  (G),  7  centimeters  in 
diameter  at  the  base,  4  centimeters  high,  resting  on  a  glass  plate  (//) 
about  10  centimeters  square. 

23.  Method. — In  making  the  determination,  the  same  quantity  of 
cement  as  will  be  used  subsequently  for  each  batch  in  making  the  test 
pieces,  but  not  less  than  500  grams,  with  a  measured  quantity  of  water, 
is  kneaded  into  a  paste,   as  described  in  paragraph  45,   and  quickly 
formed  into  a  ball  with  the  hands,  completing  the  operation  by  tossing 
it  six  times  from  one  hand  to  the  other,  maintained  about  6  inches 
apart;  the  ball  resting  in  the  palm  of  one  hand  is  pressed  into  the 
larger  end  of  the  rubber  ring  held  in  the  other  hand,  completely  filling 
the  ring  with  paste ;  the  excess  at  the  larger  end  is  then  removed  by  a 
single  movement  of  the  palm  of  the  hand;  the  ring  is  then  placed  on 
its  larger  end  on  a  glass  plate  and  the  excess  paste  at  the  smaller  end 
is  sliced  off  at  the  top  of  the  ring  by  a  single  oblique  stroke  of  a 
trowel  held  at  a  slight  angle  with  the  top  of  the  ring.     During  these 
operations  care  must  be  taken  not  to  compress  the  paste.     The  paste 
confined  in  the  ring,  resting  on  the  plate,  is  placed  under  the  rod,  the 
larger  end  of  which  is  brought  in  contact  with  the  surface  of  the 
paste;  the  scale  is  then  read,  and  the  rod  quickly  released. 

24.  The  paste  is  of  normal  consistency  when  the  cylinder  settles 
to  a  point  10  millimeters  below  the  original  surface  in  l/2  minute  after 
being  released.    The  apparatus  must  be  free  from  all  vibrations  during 
the  test. 

25.  Trial  pastes  are  made  with  varying  percentages  of  water  until 
the  normal  consistency  is  obtained. 

26.  Having  determined  the  percentage  of  water  required  to  pro- 
duce a  paste  of   normal   consistency,  the  percentage   required   for  a 
mortar  containing,  by  weight,  I  part  of  cement  to  3  parts  of  standard 
Ottawa  sand,  is  obtained  from  the  following  table,  the  amount  .being 
a  percentage  of  the  combined  weight  of  the  cement  and  sand. 


255 


PERCENTAGE  OF  WATER  FOR  STANDARD  MORTARS. 


One  cement, 

One  cement, 

One  cement, 

Neat 

three  standard 

Neat 

three  standard 

Neat 

three  standard 

Ottawa  sand 

Ottawa  sand 

Ottawa  sand 

15 

8.0 

23 

9-3 

31 

10.7 

16 

8.2 

24 

9-5 

32 

10.8 

17 

8-3 

25 

9-7 

33 

II.O 

18 

8.5 

26 

9.8 

34 

II.  2 

19 

8.7 

27 

10.0 

35 

ii.  3 

20 

8.8 

28 

10.2 

36 

H.5 

21 

9.0 

29 

10.3 

37 

11.7 

22 

9.2 

30 

10.5 

38 

11.8 

TIME  OE  SETTING. 

27.  Significance. — The  object  of  this  test  is  to  determine  the  time 
which  elapses  from  the  moment  water  is  added  until  the  paste  ceases 
to  be  plastic  (called  the  "initial  set"),  and  also  the  time  until  it  acquires 
a  certain  degree  of  hardness    (called  the  "final  set"  or  "hard  set"). 
The  former  is  the  more  important,  since,  with  the  commencement  of 
setting,  the  process  of  crystallization  begins.     As  a  disturbance  of  this 
process  may  produce  a  loss  of  strength,  it  is  desirable  to  complete  the 
operation  of  mixing  or  molding  or  incorporating  the  mortar  into  the 
work  before  the  cement  begins  to  set. 

28.  Apparatus. — The    initial    and   final    set    should   be    determined 
with  the  Vicat  apparatus  described  in  paragraph  22. 

29.  Method. — x\  paste  of  normal  consistency  is  molded  in  the  hard 
rubber  ring,  as  described  in  paragraph  23,  and  placed  under  the  rod 
(B),  the  smaller  end  of  which  is  then  carefully  brought  in  contact 
with  the  surface  of  the  paste,  and  the  rod  quickly  released. 

30.  The  initial  set  is  said  to  have  occurred  when  the  needle  ceases 
to  pass  a  point  5  millimeters  above  the  glass  plate;  and  the  final  set, 
when  the  needle  does  not  sink  visibly  into  the  paste. 

31.  The  test  pieces  should  be  kept  in  moist  air  during  the  test; 
this  may  be  accomplished  by  placing  them  on  a  rack  over  water  con- 
tained in  a  pan  and  covered  by  a  damp  cloth ;  the  cloth  to  be  kept  from 
contact  with  them  by  means  of  a  wire  screen;  or  they  may  be  stored 
in  a  moist  box  or  closet. 

32.  Care  should  be  taken  to  keep  the  needle  clean,  as  the  collection 
of  cement  on  the  sides  of  the  needle  retards  the  penetration,  while 
cement  on  the  point  may  increase  the  penetration. 

33.  The  time  of  setting  is  affected  not  only  by  the  percentage  and 
temperature  of  the  water  used  and  the  amount  of  kneading  the  paste 
receives,  but  by  the  temperature  and  humidity  of  the  air,  and  its  deter- 
mination is,  therefore,  only  approximate. 


256 


STANDARD  SAND. 

34.  The  sand  to  be  used  should  be  natural  sand  from  Ottawa,  111., 
screened  to  pass  a  No.  20  sieve,  and  retained  on  a  No.  30  sieve.  The 
sieves  should  be  at  least  8  inches  in  diameter;  the  wire  cloth  should 
be  of  brass  wire  and  should  conform  to  the  following  requirements : 


No.  of  sieve 

Diameter  of  wire, 
inches 

Meshes,  per  linear  inch 

Warp 

Woof 

2O 
30 

0.016  to  0.017 

O.OII  tO  O.OI2 

19.5  to  20.5 
29.5  to  30.5 

19       to  21 

28.5  to  31.5 

FIG.  64.— Details  for  Briquet. 


257 


Sand  which  has  passed  the  No.  20  sieve  is  standard  when  not  more 
than  5  grams  passes  the  No.  30  sieve  in  I  minute  of  continuous  sift- 
ing of  a  5oo-gram  sample.1 

FORM  OF  TEST  PIECES. 

35.  For  tensile  tests  the  form  of  test  piece  shown  in  Fig.  55  should 
be  used. 

36.  For  compressive  tests,  2-inch  cubes  should  be  used. 

MOLDS. 

37.  The  molds  should  be  of  brass,  bronze,  or  other  non-corrodible 
material,    and   should   have    sufficient   metal   in   the   sides    to   prevent 
spreading  during  molding. 

38.  Molds  may  be  either  single  or  gang  molds.    The  latter  are  pre- 
ferred by  many.     If  used,  the  types  shown  in   Figs.  65  and  66  are 
recommended. 


FIG.  65.— Details  for  Gang  Mold. 


FIG.  66. -Mold  for  Compression  Test  Pieces. 


39.  The  molds  should  be  wiped  with  an  oily  cloth  before  using. 

MIXING. 

40.  The    proportions    of    sand    and    cement    should    be    stated   by 
weight;   the  quantity  of  water  should  be  stated  as  a  percentage  by 
weight  of  the  dry  material. 

41.  The  metric  system  is  recommended  because  of  the  convenient 
relation  of  the  gram  and  the  cubic  centimeter. 

42.  The  temperature  of  the  room  and  of  the  mixing  water  should 
be  maintained  as  nearly  as  practicable  at  21°  C.   (70°  F.). 

*  This  sand  may  now  (1912)  be  obtained  from  the  Ottawa  Silica  Co.,  at  a  cost  of  two 
cents  per  pound,  f.  o.  b.  cars,  Ottawa,  111. 


258 

43.  The  quantity  of  material  to  be  mixed  at  one  time  depends  on 
the  number  of  test  pieces  to  be  made;  1,000  grams  is  a  convenient  quan- 
tity to  mix  by  hand  methods. 

44.  The  Committee  has  investigated  the  various  mechanical  mix- 
ing machines  thus   far  devised,  but  cannot  recommend   any  of  them, 
for  the   following  reasons:      (i)    the  tendency  of  most  cement  is  to 
"ball  up"  in  the  machine,  thereby  preventing  working  it  into  a  homo- 
geneous paste;   (2)  there  are  no  means  of  ascertaining  when  the  mix- 
ing is  complete  without  stopping  the  machine;   and    (3)   it  is  difficult 
to  keep  the  machine  clean. 

45.  Method. — The  material  is  weighed,  placed  on  a  non-absorbent 
surface    (preferably   plate    glass),   thoroughly   mixed   dry   if    sand   be 
used,  and  a  crater  formed  in  the  center,  into  which  the  proper  per- 
centage of  clean  water  is  poured ;  the  material  on  the  outer  edge  is 
turned  into  the  center  by  the  aid  of  a  trowel.     As  soon  as  the  water 
has  been  absorbed,  which  should  not  require  more  than  i  minute,  the 
operation  is   completed   by  vigorously  kneading  with   the  hands    for 
i   minute.     During  the  operation  the  hands   should  be   protected  by 
rubber  gloves. 

MOLDING. 

46.  The  Committee  has  not  been  able  to  secure  satisfactory  results 
with  existing  molding  machines ;  the  operation  of  machine  molding  is 
very  slow;  and  is  not  practicable  with  pastes  or  mortars  containing  as 
large  percentages  of  water  as  herein  recommended. 

47.  Method. — Immediately   after   mixing,   the   paste   or   mortar   is 
placed  in  the  molds  with  the  hands,  pressed  in  firmly  with  the  fingers, 
and  smoothed  off  with  a  trowel  without  ramming.    The  material  should 
be  heaped  above  the  mold,  and,  in  smoothing  off,  the  trowel  should  be 
drawn  over  the  mold  in  such  a  manner  as  to  exert  a  moderate  pressure 
on  the  material.    The  mold  should  then  be  turned  over  and  the  opera- 
tion of  heaping  and  smoothing  off  repeated. 

48.  A  check  on  the   uniformity  of   mixing  and   molding  may  be 
afforded  by  weighing  the  test  pieces  on  removal  from  the  moist  closet; 
test  pieces  from  any  sample  which  vary  in  weight  more  than  3  per  cent, 
from  the  average  should  not  be  considered. 

STORAGE  OF  THE  TEST  PIECES. 

49.  During  the  first  24  hours  after  molding,  the  test  pieces  should 
be  kept  in  moist  air  to  prevent  drying. 

50.  Two  methods  are  in  common  use  to  prevent  drying:    (i)  cov- 
ering the  test  pieces  with  a  damp  cloth,  and    (2)    placing  them  in  a 
moist  closet.     The  use  of  the  damp  cloth,  as  usually  carried  out,  is 
objectionable,  because  the  cloth  may  dry  out  unequally  and  in  conse- 


259 


quence  the  test  pieces  will  not  all  be  subjected  to  the  same  degree  of 
moisture.  This  defect  may  be  remedied  to  some  extent  by  immersing 
the  edges  of  the  cloth  in  water;  contact  between  the  cloth  and  the 
test  pieces  should  be  prevented  by  means  of  a  wire  screen,  or  some 
similar  arrangement.  A  moist  closet  is  so  much  more  effective  in 
securing  uniformly  moist  air,  and  is  so  easily  devised  and  so  inexpen- 
sive, that  the  use  of  the  damp  cloth  should  be  abandoned. 


Roller  turned  and  accurately 
bored  to  easy  turning  fit 


FIG.  67.— Form  of  Clip. 


51.  A  moist  closet  consists  of  a  soapstone  or  slate  box,  or  a  wooden 
box  lined  with  metal,  the  interior  surface  being  covered  with  felt  or 
broad  wicking  kept  wet,  the  bottom  of  the  box  being  kept  covered 
with  water.  The  interior  of  the  box  is  provided  with  glass  shelves  on 
which  to  place  the  test  pieces,  the  shelves  being  so  arranged  that  they 
may  be  withdrawn  readily. 


260 


52.  After  24  hours  in  moist  air,  the  pieces  to  be  tested  after  longer 
periods  should  be  immersed  in  water  in  storage  tanks  or  pans  made 
of  non-corrodible  material. 

53.  The  air  and  water  in  the  moist  closet  and  the  water  in  the 
storage  tanks  should  be  maintained  as  nearly  as  practicable  at  21°  C. 
(70°  P.). 

TENSILE  STRENGTH. 

54.  The  tests  may  be  made  with  any  standard  machine. 

55.  The  clip  is  shown  in  Fig.  67.     It  must  be  made  accurately,  the 
pins  and  rollers  turned,  and  the  rollers  bored  slightly  larger  than  the 
pins  so  as  to  turn  easily.     There  should  be  a  slight  clearance  at  each 
end  of  the  roller,  and  the  pins  should  be  kept  properly  lubricated  and 
free  from  grit.     The  clips  should  be  used  without  cushioning  at  the 
points  of  contact. 

56.  Test  pieces  should  be  broken  as  soon  as  they  are  removed  from 
the  water.     Care  should  be  observed  in  centering  the  test  pieces  in 
the  testing  machine,  as  cross  strains,  produced  by  imperfect  centering, 
tend  to  lower  the  breaking  strength.     The  load  should  not  be  applied 
too  suddenly,  as  it  may  produce  vibration,  the  shock  from  which  often 
causes  the  test  pieces  to  break  before  the  ultimate  strength  is  reached. 
The  bearing  surfaces  of  the  clips  and  test  pieces  must  be  kept  free 
from  grains  of  sand  or -dirt,  which  would  prevent  a  good  bearing.    The 
load  should  be  applied  at  the  rate  of  600  pounds  per  minute.     The 
average  of  the  results  of  the  test  pieces  from  each  sample  should  be 
taken  as  the  test  of  the  sample.    Test  pieces  which  do  not  break  within 
J4  inch  of  the  center,  or  are  otherwise  manifestly  faulty,   should  be 
excluded  in  determining  average  results. 

COMPRESSIVE  STRENGTH. 

57.  The  tests  may  be  made  with  any  machine  provided  \vith  means 
for  so  applying  the  load  that  the  line  of  pressure  is  along  the  axis  of 
the  test  piece.     A   ball-bearing  block   for   this   purpose  is   shown  in 
Fig.  68.     Some  appliance  should  be  provided  to  facilitate  placing  the 
axis  of  the  test  piece  exactly  in  line  with  the  center  of  the  ball-bearing. 

58.  The  test  piece  should  be  placed  in  the  testing  machine,  with  a 
piece  of  heavy  blotting  paper  on   each  of  the   crushing   faces,  which 
should  be  those  that  were  in  contact  with  the  mold. 

CONSTANCY  OF  VOLUME. 

59.  Significance. — The  object  is  to  detect  those  qualities  which  tend 
to   destroy  the  strength  and  durability  of   a  cement.     Under  normal 
conditions  these  defects  will  in  some  cases  develop  quickly,   and  in 


26 1 


•other  cases  may  not  develop  for  a  considerable  time.  Since  the  detec- 
tion of  these  destructive  qualities  before  using  the  cement  in  con- 
struction is  essential,  tests  are  made  not  only  under  normal  conditions 
but  under  artificial  conditions  created  to  hasten  the  development  of 
these  defects.  Tests  may,  therefore,  be  divided  into  two  classes : 
(i)  Normal  tests,  made  in  either  air  or  water  maintained,  as  nearly 
-as  practicable,  at  21°  C.  (70°  F.)  ;  and  (2)  Accelerated  tests,  made  in 


^%££^%^ 

FIG.  68.— Ball-bearing  Block  for  Testing  Machine. 

air,  steam  or  water,  at  temperature  of  45°  C.  (113°  F.)  and  upward. 
The  Committee  recommends  that  these  tests  be  made  in  the  following 
manner : 

60.  Methods. — Pats,  about  3  inches  in  diameter,   %  inch  thick  at 
the  center,  and  tapering  to  a  thin  edge,  should  be  made  on  clean  glass 
plates   (about  4  inches  square)   from  cement  paste  of  normal  consist- 
ency, and  stored  in  a  moist  closet  for  24  hours. 

61.  Normal  Tests. — After  24  hours  in  the  moist  closet,  a  pat  is 
immersed  in  water  for  28  days  and  observed  at  intervals.     A  similar 


262 


pat,  after  24  hours  in  the  moist  closet,  is  exposed  to  the  air  for  28  days 
or  more  and  observed  at  intervals. 

62.  Accelerated  Test.— After  24  hours  in  the  moist  closet,  a  pat  is 
placed  in  an  atmosphere  of  steam,  upon  a  wire  screen  I  inch  above 
boiling  water,  for  5  hours.     The  apparatus  should  be  so  constructed 
that  the  steam  will  escape  freely  and  atmospheric  pressure  be  main- 
tained.    Since  the  type  of  apparatus  used  has  a  great  influence  on  the 
results,  the  arrangement  shown  in  Fig.  69  is  recommended. 

63.  Pats  which  remain  firm  and  hard  and  show  no  signs  of  crack- 
ing distortion,  or  disintegration  are  said  to  be  "of  constant  volume" 
or  "sound." 

64.  Should  the  pat  leave  the  plate,  distortion  may  be  detected  best 
with  a  straight-edge  applied  to  the  surface  which  was  in  contact  with 
the  plate. 

65.  In  the  present  state  of  our  knowledge  it  cannot  be  said  that  a 
cement  which  fails  to  pass  the  accelerated  test  will  prove  defective  in 
the  work ;  nor  can  a  cement  be  considered  entirely  safe  simply  because 
it  has  passed  these  tests. 

METHODS  FOR  TESTING  CEMENT.1 
Condensed  for  Use  in  Specifications. 

i.    SAMPLING. 

Cement  in  barrels  shall  be  sampled  through  a  hole  made  in  the 
head,  or  in  one  of  the  staves  midway  between  the  heads,  by  means  of 
an  auger  or  a  sampling  iron  similar  to  that  used  by  sugar  inspectors; 
if  in  bags,  the  sample  shall  be  taken  from  surface  to  center.  Cement 
in  bins  shall  be  sampled  in  such  a  manner  as  to  represent  fairly  the 
contents  of  the  bin.  The  number  of  samples  taken  shall  be  as  directed 
by  the  engineer,  who  will  determine  whether  the  samples  shall  be 
tested  separately  or  mixed. 

The  samples  shall  be  passed  through  a  sieve  having  twenty  meshes 
per  linear  inch,  in  order  to  break  up  lumps  and  remove  foreign 
material. 

2.   CHEMICAL,  ANALYSIS. 

The  methods  to  be  followed,  except  for  determining  the  loss  on 
ignition,  should  be  those  proposed  by  the  Committee  on  Uniformity 
in  the  Analysis  of  Materials  for  the  Portland  Cement  Industry,  re- 
ported in  the  Journal  of  the  Society  for  Chemical  Industry,  Vol.  21, 
p.  12,  1902,  and  published  in  Engineering  News,  Vol.  50,  p.  60,  1903, 
and  in  Engineering  Record,  Vol.  48,  p.  49,  1903,  and  in  addition  thereto 
the  following: 

1  Accompanying  Final  Report  of  Special  Committee  on  Uniform  Tests  of  Cement 
of  the  American  Society  of  Civil  Engineers,  dated  January  17,  1912. 


263 


* 

fed 


\ 


If 


1 

•     . 

i  ^ 

^  i 
llJ_ 

»  t 

ir^ 

^  § 

\  ! 

(    ^  ^.l-ft—  -  > 

!     K;*- 

:—  7,9— 
i 
• 

! 

I 

• 
j 

1  kl                IFTj 
// 

i 

Re 

\ 

°5 

il 


111 
*\i 

ill 


/ 


rrHfe 

^r-F 


S  oJ 

|i 

li 


5^ 

2    rr 


264 

(a)  The  insoluble  residue  may  be  determined  as  follows :  To  a 
i -gram  sample  of  the  cement  are  added  30  cubic  centimeters  of  water 
and  10  cubic  centimeters  of  concentrated  hydrochloric  acid,  and  then 
warmed  until  effervescence  ceases,  and  digested  on  a  steam  bath  until 
dissolved.  The  residue  is  filtered,  washed  with  hot  water,  and  the 
filter  paper  and  contents  digested  on  the  steam  bath  in  a  5  per  cent, 
solution  of  sodium  carbonate.  This  residue  is  filtered,  washed  with 
hot  water,  then  with  hot  hydrochloric  acid,  and  finally  with  hot  water, 
and  then  ignited  at  a  red  heat  and  weighed.  The  quantity  so  obtained 
is  the  insoluble  residue. 

(&)  The  loss  on  ignition  shall  be  determined  in  the  following 
manner :  One-half  gram  of  cement  is  heated  in  a  weighed  platinum 
crucible,  with  cover,  for  5  minutes  with  a  Bunsen  burner  (starting 
with  a  low  flame  and  gradually  increasing  to  its  full  height)  and  then 
heated  for  15  minutes  with  a  blast  lamp;  the  difference  between  the 
weight  after  cooling  and  the  original  weight  is  the  loss  on  ignition. 
The  temperature  should  not  exceed  900°  C.,  or  a  low  red  heat ;  the 
ignition  should  preferably  be  made  in  a  muffle. 

3.    SPECIFIC  GRAVITY. 

The  determination  of  specific  gravity  shall  be  made  with  a  stand- 
ardized Le  Chatelier  apparatus.  This  consists  of  a  flask  (D),  Fig.  62, 
p.  251,  of  about  120  cubic  centimeters  capacity,  the  neck  of  which  is 
about  20  centimeters  long;  in  the  middle  of  this  neck  is  a  bulb  (C), 
above  and  below  which  are  two  marks  (F)  and  (B)  ;  the  volume 
between  these  two  marks  is  20  cubic  centimeters.  The  neck  has  a 
diameter  of  9  millimeters,  and  is  graduated  into  tenths  of  cubic  centi- 
meters above  the  mark  (F). 

Benzene  (62°  Baume  naphtha)  or  kerosene  free  from  water  shall 
be  used  in  making  the  determination.  The  flask  is  filled  with  either 
of  these  liquids  to  the  lower  mark  (£)  and  64  grams  of  cement,  cooled 
to  the  temperature  of  the  liquid,  is  slowly  introduced  through  the 
funnel  (B),  the  stem  of  which  should  be  long  enough  to  extend  into 
the  flask  to  the  top  of  the  bulb  (C),  taking  care  that  the  cement  does 
not  adhere  to  the  sides  of  the  flask,  and  that  the  funnel  does  not  touch 
the  liquid.  After  all  the  cement  is  introduced,  the  level  of  the  liquid 
will  rise  to  some  division  of  the  graduated  neck;  this  reading,  plus 
20  cubic  centimeters,  is  the  volume  displaced  by  64  grams  of  the 
cement.  The  specific  gravity  is  obtained  from  the  formula, 

Weight  of  cement,  in  grams 
Spec    ic  gravity  =  Displaced  volume>  jn  cubic  centimeters. 

The  flask,  during  the  operation,  is  kept  immersed  in  water  in  a 
jar  (A)  in  order  to  avoid  variations  in  the  temperature  of  the  liquid 
in  the  flask,  which  shall  not  exceed  T/2°  C.  The  results  of  repeated 


tests  shall  agree  within  o.oi.  The  determination  of  specific  gravity 
shall  be  made  on  the  cement  as  received;  if  it  should  fall  below  3.10, 
a  second  determination  shall  be  made  after  igniting  the  sample  in  a 
covered  dish,  preferably  of  platinum,  at  a  low  red  heat  not  exceeding 
900°  C.  The  sample  shall  be  heated  for  5  minutes  with  a  Bunsen 
burner  (starting  with  a  low  flame  and  gradually  increasing  to  its  full 
height)  and  then  heated  for  15  minutes  with  a  blast  lamp;  the  ignition 
should  preferably  be  made  in  a  muffle. 

4.    FINENESS. 

The  fineness  shall  be  determined  by  weighing  the  residue  retained 
on  No.  100  and  No.  200  sieves.  The  sieves,  8  inches  in  diameter,  shall 
be  of  brass  wire  cloth  conforming  to  the  following  requirements : 


No.  of  sieve 

Diameter  of  wire, 
inches 

Meshes,  per  linear  inch 

Warp 

Woof 

100 
200 

0.0042  to  0.0048 
0.0021  to  0.0023 

95  to  ioi 
192  to  203 

93  to  103 
190  to  205 

The  meshes  in  any  smaller  space,  down  to  0.25  inch,  shall  be  pro- 
portional in  number. 

Fifty  grams  of  cement,  dried  at  a  temperature  of  100°  C.  (212°  F.), 
shall  be  placed  on  the  No.  200  sieve,  which,  with  pan  and  cover 
attached,  is  held  in  one  hand  in  a  slightly  inclined  position,  and  moved 
forward  and  backward  about  200  times  per  minute,  at  the  same  time 
striking  the  side  gently,  on  the  up  stroke,  against  the  palm  of  the  other 
hand.  The  operation  is  continued  until  not  more  than  0.05  gram  will 
pass  through  in  I  minute.  The  residue  is  weighed,  then  placed  on  the 
No.  100  sieve,  and  the  operation  repeated.  The  work  may  be  expedited 
by  placing  in  the  sieve  a  few  large  steel  shot,  which  should  be  removed 
before  the  final  I  minute  of  sieving.  The  sieves  should  be  thoroughly 
dry  and  clean. 

5.   NORMAI,  CONSISTENCY. 

The  amount  of  water,  expressed  in  percentage  by  weight  of  the 
dry  cement,  required  to  produce  a  paste1  of  the  plasticity  desired, 
termed  "normal  consistency,"  shall  be  determined  with  the  Vicat 
apparatus : 

1  The  term  "paste"  is  used  in  these  specifications  to  designate  a  mixture  of  cement 
and  water,  and  the  word  "mortar"  to  designate  a  mixture  of  cement,  sand  and  water. 


266 

This  consists  of  a  frame  (A),  Fig.  63,  p.  253,  bearing  a  movable 
rod  (#),  weighing  300  grams,  one  end  (C)  being  I  centimeter  in 
diameter  for  a  distance  of  6  centimeters,  the  other  having  a  removable 
needle  (D),  i  millimeter  in  diameter,  6  centimeters  long.  The  rod  is 
reversible,  and  can  be  held  in  any  desired  position  by  a  screw  (£), 
and  has  midway  between  the  ends  a  mark  (F)  which  moves  under  a 
scale  (graduated  to  millimeters)  attached  to  the  frame  (A).  The 
paste  is  held  in  a  conical,  hard-rubber  ring  ((7),  7  centimeters  in  diam- 
eter at  the  base,  4  centimeters  high,  resting  on  a  glass  plate  (H )  about 
10  centimeters  square. 

In  making  the  determination  of  normal  consistency,  the  same 
quantity  of  cement  as  will  be  used  subsequently  for  each  batch  in 
making  the  test  pieces,  but  not  less  than  500  grams,  together  with  a 
measured  amount  of  water,  is  kneaded  into  a  paste,  as  described  in 
Section  9,  and  quickly  formed  into  a  ball  with  the  hands,  completing 
the  operation  by  tossing  it  six  times  from  one  hand  to  the  other,  main- 
tained about  6  inches  apart;  the  ball  resting  in  the  palm  of  one  hand 
is  pressed  into  the  larger  end  of  the  rubber  ring  held  in  the  other 
hand,  completely  filling  the  ring  with  paste;  the  excess  at  the  larger 
end  is  then  removed  by  a  single  movement  of  the  palm  of  the  hand; 
the  ring  is  then  placed  on  its  larger  end  on  a  glass  plate  and  the  excess 
paste  at  the  smaller  end  is  sliced  off  at  the  top  of  the  ring  by  a  single 
oblique  stroke  of  a  trowel  held  at  a  slight  angle  with  the  top  of  the 
ring.  During  these  operations  care  must  be  taken  not  to  compress  the 
paste.  The  paste  confined  in  the  ring,  resting  on  the  plate,  is  placed 
under  the  rod,  the  larger  end  of  which  is  carefully  brought  in  contact 
with  the  surface  of  the  paste ;  the  scale  is  then  read,  and  the  rod  quickly 
released. 

The  paste  is  of  normal  consistency  when  the  cylinder  settles  to  a 
point  10  millimeters  below  the  original  surface  in  Y?  minute  after 
being  released.  The  apparatus  must  be  free  from  all  vibrations  during 
the  test. 

Trial  pastes  are  made  with  varying  percentages  of  water  until  the 
normal  consistency  is  attained. 

Having  determined  the  percentage  of  water  required  to  produce 
a  paste  of  normal  consistency,  the  percentage  required  for  a  mortar 
containing,  by  weight,  I  part  of  cement  to  3  parts  of  standard  Ottawa 
sand,  shall  be  obtained  from  the  following  table,  the  amount  being  a 
percentage  of  the  combined  weight  of  the  cement  and  sand. 


267 


PERCENTAGE  OF  WATER  FOR  STANDARD  MORTARS. 


Neat 

One  cement, 
three  standard 
Ottawa  sand 

Neat 

One  cement, 
three  standard 
Ottawa  sand 

Neat 

One  cement, 
three  standard 
Ottawa  sand 

15 

8.0 

23 

9-3 

31 

10.7 

16 

8.2 

24 

9-5 

32 

10.8 

17 

8-3 

25 

9-7 

33 

II.O 

18 

8.5 

26 

9.8 

34 

II.  2 

19 

8.7 

27 

IO.O 

35 

"•3 

2O 

8.8 

28 

10.2 

36 

H-5 

21 

9.0 

29 

I0.3 

37 

ii.  7 

22 

9.2 

30 

10.5 

38 

ix.8 

6.   TIME;  OF  SETTING. 

The  time  of  setting  shall  be  determined  with  the  Vicat  apparatus 
in  the  following  manner: 

A  paste  of  normal  consistency  is  molded  in  the  hard-rubber  ring, 
as  described  in  Section  5,  and  placed  under  the  rod  (5),  the  smaller 
end  of  which  is  then  carefully  brought  in  contact  with  the  surface  of 
the  paste,  and  the  rod  quickly  released. 

The  cement  is  considered  to  have  acquired  its  initial  set  when  the 
needle  ceases  to  pass  a  point  5  millimeters  above  the  glass  plate ;  and 
the  final  set,  when  the  needle  does  not  sink  visibly  into  the  paste. 

The  test  pieces  must  be  kept  in  moist  air  during  the  test. 

7.    STANDARD  SAND. 

The  sand  shall  be  natural  sand  from  Ottawa,  111.,  screened  to  pass 
a  No.  20  sieve,  and  retained  on  a  No.  30  sieve. 

The  sieves  shall  be  at  least  8  inches  in  diameter,  and  the  wire 
cloth  shall  be  of  brass  wire  and  shall  conform  to  the  following 
requirements : 


No.  of  sieve 

Diameter  of  wire, 
inches 

Meshes,  per  linear  inch 

Warp 

Woof 

20 
30 

0.016  to  0.017 

O.OII  tO  0.012 

19.5  to  20.5 
29-5  to  30.5 

19      tO  21 

28.5  to  31.5 

Sand  which  has  passed  the  No.  20  sieve  is  standard  when  not  more 
than  5  grams  pass  the  No.  30  sieve  in  I  minute  of  continuous  sifting 
of  a  5OO-gram  sample.1 

1  This  sand  may  now  (1912)  be  obtained  from  the  Ottawa  Silica  Co.,  at  a  cost  of  two 
cents  per  pound,  f .  o.  b.  cars,  Ottawa,  111. 


268 


8.  FORM  OE  TEST  PIECES. 

For  tensile  tests,  the  form  of  test  pieces  shown  in  Fig.  64,  p.  256^. 
shall  be  used. 

For  compressive  tests,  2-inch  cubes  shall  be  used. 

9.  MIXING  AND  MOLDING. 

The  material  shall  be  weighed,  placed  on  a  non-absorbent  surface, 
thoroughly  mixed  dry  if  sand  be  used,  and  a  crater  formed  in  the 
center,  into  which  the  proper  percentage  of  clean  water  shall  be 
poured;  the  material  on  the  outer  edge  shall  be  turned  into  the  center 
by  the  aid  of  a  trowel.  As  soon  as  the  water  has  been  absorbed,  the 
operation  of  mixing  shall  be  completed  by  vigorously  kneading  with 
the  hands  for  I  minute. 

Immediately  after  mixing,  the  paste  or  mortar  shall  be  placed  in 
the  mold  (Figs.  65  and  66,  p.  257)  with  the  hands,  pressed  in  firmly 
with  the  fingers,  and  smoothed  off  with  a  trowel  without  ramming. 
The  material  shall  be  heaped  above  the  mold,  and,  in  smoothing  off,, 
the  trowel  shall  be  drawn  over  the  mold  in  such  a  manner  as  to  exert 
a  moderate  pressure  on  the  material ;  the  mold  shall  then  be  turned 
over  and  the  operation  of  heaping  and  smoothing  off  repeated. 

The  temperature  of  the  room  and  of  the  mixing  water  shall  be 
maintained  as  nearly  as  practicable  at  21°  C.  (70°  F.). 

10.  STORAGE  OF  THE  TEST  PIECES. 

During  the  first  24  hours  after  molding,  the  test  pieces  shall  be 
stored  in  a  moist  closet.  This  consists  of  a  box  of  soapstone  or  slate, 
or  of  wood  lined  with  metal,  the  interior  surface  being  covered  with 
felt  or  broad  wicking  kept  wet,  the  bottom  of  the  box  being  kept  cov- 
ered with  water.  The  interior  of  the  box  is  provided  with  glass 
shelves  on  which  to  place  the  test  pieces,  the  shelves  being  so  arranged 
that  they  may  be  withdrawn  readily. 

Test  pieces  from  any  sample  which  vary  more  than  3  per  cent,  in 
weight  from  the  average,  after  removal  from  the  moist  closet,  shall 
not  be  considered  in  determining  strength. 

After  24  hours  in  the  moist  closet,  the  pieces  to  be  tested  after 
longer  periods  shall  be  immersed  in  water  in  storage  'tanks  or  pans 
made  of  non-corrodible  material. 

The  air  and  water  in  the  moist  closet  and  the  water  in  the  storage 
tanks  shall  be  maintained,  as  nearly  as  practicable,  at  21°  C.  (70°  F.). 

11.  TESTS  OF  TENSILE  STRENGTH. 

The  tests  may  be  made  with  any  standard  machine. 
The  clip  is  shown  in  Fig.  67,  p.  259.    It  must  be  made  accurately, 
the  pins  and  rollers  turned,  and  the  rollers  bored  slightly  larger  than 


269 

the  pins  so  as  to  turn  easily.  There  should  be  a  slight  clearance  at 
each  end  of  the  roller,  and  the  pins  should  be  kept  properly  lubricated 
and  free  from  grit.  The  clips  shall  be  used  without  cushioning  at 
the  points  of  contact. 

The  test  pieces  shall  be  broken  as  soon  as  they  are  removed  from 
the  water.  The  load  shall  be  applied  at  the  rate  of  600  pounds  per 
minute. 

Test  pieces  which  do  not  break  within  J4  inch  of  the  center,  or 
are  otherwise  manifestly  faulty,  shall  be  excluded  in  determining 
average  results. 

12.   TESTS  OF  COMPRESSIVE  STRENGTH. 

The  tests  may  be  made  with  any  machine  provided  with  means 
for  so  applying  the  load  that  the  line  of  pressure  is  along  the  axis  of 
the  test  piece.  A  ball-bearing  block  for  this  purpose  is  shown  in  Fig. 
68,  p.  261. 

The  test  pieces  as  soon  as  they  are  removed  from  the  water  shall 
be  placed  in  the  testing  machine,  with  a  piece  of  heavy  blotting  paper 
on  each  of  the  crushing  faces,  which  should  be  those  that  were  in 
contact  with  the  mold. 

13.    CONSTANCY  OF  VOLUME. 

Tests  for  constancy  of  volume  comprise  "normal  tests"  which  are 
made  in  air  or  water,  maintained  as  nearly  as  practicable,,  at  21°  C. 
(70°  F.),  and  the  "accelerated  test,"  which  is  made  in  steam.  These 
tests  shall  be  made  in  the  following  manner : 

Pats  about  3  inches  in  diameter,  ~*/2  inch  thick  at  the  center,  and 
tapering  to  a  thir  edge,  shall  be  made  on  clean  glass  plates  (about  4 
inches  square)  from  cement  paste  of  normal  consistency,  and  stored 
in  a  moist  closet  for  24  hours. 

Normal  Tests. — After  24  hours  in  the  moist  closet,  a  pat  is  im- 
mersed in  water  and  observed  at  intervals.  A  similar  pat,  after  24 
hours  in  the  moist  closet,  is  exposed  to  the  air  for  28  days  or  more 
and  observed  at  intervals.  The  air  and  water  are  maintained,  as  nearly 
as  practicable,  at  21°  C.  (70°  F.). 

Accelerated  Test. — After  24  hours  in  the  moist  closet,  a  pat  is 
placed  in  an  atmosphere  of  steam,  upon  a  wire  screen  I  inch  above 
boiling  water,  for  5  hours,  the  apparatus  being  such  that  the  steam 
will  escape  freely  and  atmospheric  pressure  be  maintained.  The 
apparatus  is  shown  in  Fig.  69,  p.  263. 

The  cement  passes   these  tests   when  the  pats   remain   firm  and 
hard,  with  no  signs  of  cracking,  distortion,  or  disintegration. 
18 


270 

APPENDIX. 

METHODS  FOR  THE  CHEMICAL  ANALYSIS  OF 

LIMESTONES,  RAW  MIXTURES  AND 

PORTLAND  CEMENTS. 

Recommended  by  the  Committee  on  Uniformity  in  Technical 

Analysis  of  the  New  York  Section  of  the  Society 

for  Chemical  Industry. 

Solution. — One-half  gram  of  the  finely  powdered  substance  is  to- 
be  weighed  out  and,  if  a  limestone  or  unburned  mixture,  strongly 
ignited  in  a  covered  platinum  crucible  over  a  strong  blast  for  15 
minutes,  or  longer  if  the  blast  is  not  powerful  enough  to  effect  com- 
plete conversion  to  a  cement  in  this  time.  It  is  then  transferred  to  an 
evaporating  dish,  preferably  of  platinum  for  the  sake  of  celerity  in 
evaporation,  moistened  with  enough  water  to  prevent  lumping,  and 
5  to  10  cubic  centimeters  of  strong  HC1  added  and  digested  with  the 
aid  of  gentle  heat  and  agitation  until  solution  is  complete.  Solution 
may  be  aided  by  light  pressure  with  the  flattened  end  of  a  glass  rod.1 
The  solution  is  then  evaporated  to  dryness,  as  far  as  this  may  be 
possible  on  the  bath. 

Silica  (5V02). — The  residue  without  further  heating  is  treated  at 
first  with  5  to  10  cubic  centimeters  of  strong  HC1,  which  is  then 
diluted  to  half  strength  or  less,  or  upon  the  residue  may  be  poured  at 
once  a  larger  volume  of  acid  of  half  strength.  The  dish  is  then 
covered  and  digestion  allowed  to  go  on  for  10  minutes  on  the  bath, 
after  which  the  solution  is  filtered  and  the  separated  silica  washed 
thoroughly  with  water.  The  filtrate  is  again  evaporated  to  dryness, 
the  residue  without  further  heating,  taken  up  with  acid  and  water  and 
the  small  amount  of  silica  it  contains  separated  on  another  filter  paper. 
The  papers  containing  the  residue  are  transferred  wet  to  a  weighed 
platinum,  crucible,  dried,  ignited,  first  over  a  Bunsen  burner  until  the 
carbon  of  the  filter  is  completely  consumed,  and  finally  over  the  blast 
for  15  minutes  and  checked  by  a  further  blasting  for  10  minutes  or 
to  constant  weight.  The  silica,  if  great  accuracy  is  desired,  is  treated 
in  the  crucible  with  about  10  cubic  centimeters  of  HF1  and  four  drops 
of  H2SO4  and  evaporated  over  a  low  flame  to  complete  dryness.  The 
small  residue  is  finally  blasted,  for  a  minute  or  two,  cooled  and 
weighed.  The  difference  between  this  weight  and  the  weight  previously 
obtained  gives  the  amount  of  silica.2 

1  If  anything  remains  undecomposed  it  should  be  separated,  fused  with  a  little 
Na2COo,  dissolved  and  added  to  the  original  solution.     Of  course  a  small  amount  of 
separated  non-gelatinous  silica  is  not  to  be  mistaken  for  undecomposed  matter. 

2  For  ordinary  control  in  the  plant  laboratory  this  correction  may,  perhaps,  be  neg- 
lected; the  double  evaporation  never. 


271 

Alumina  and  Iron  (A1203  and  FezO3).— The  filtrate,  about  250 
cubic  centimeters,  from  the  second  evaporation  for  SiOz,  is  made  alka- 
line with  NHUOH  after  adding  HC1,  if  need  be,  to  insure  a  total  of 
10  to  15  cubic  centimeters  strong  acid,  and  boiled  to  expel  excess 
of  NH3,  or  until  there  is  but  a  faint  odor  of  it,  and  the  precipitate  iron 
and  aluminum  hydrates,  after  settling,  are  washed  once  by  decanta- 
tion  and  slightly  on  the  filter.  Setting  aside  the  filtrate,  the  precipitate 
is  dissolved  in  hot  dilute  HC1,  the  solution  passing  into  the  beaker  in 
which  the  precipitation  was  made.  The  aluminum  and  iron  are  then 
reprecipitated  by  NHUOH,  boiled  and  the  second  precipitate  collected 
and  washed  on  the  same  filter  used  in  the  first  instance.  The  filter 
paper,  with  the  precipitate,  is  then  placed  in  a  weighed  platinum 
crucible,  the  paper  burned  off  and  the  precipitate  ignited  and  finally 
blasted  5  minutes,  with  care  to  prevent  reduction,  cooled  and  weighed 
as  A12O3  -f  FesOs.1 

Iron  (Fe^Os). — The  combined  iron  and  aluminum  oxides  are  fused 
in  a  platinum  crucible  at  a  very  low  temperature  with  about  3  to  4 
grams  of  KHSO<,  or,  better,  NaHSO-i,  the  melt  taken  up  with  so  much 
dilute  H2SO4  that  there  shall  be  no  less  than  5  grams  absolute  acid 
and  enough  water  to  effect  solution  on  heating.  The  solution  is  then 
evaporated  and  eventually  heated  till  acid  fumes  come  off  copiously. 
After  cooling  and  redissolving  in  water  the  small  amount  of  silica  is 
filtered  out,  weighed  and  corrected  by  HF1  and  HzSCk2  The  filtrate 
is  reduced  by  zinc,  or  preferably  by  hydrogen  sulphide,  boiling  out 
the  excess  of  the  latter  afterwards  while  passing  CO2  through  the 
flask,  and  titrated  with  permanganate.3  The  strength  of  the  perman- 
ganate solution  should  not  be  greater  than  0.0040  gram  Fe2O3  per 
cubic  centimeter. 

Lime  (CaO).— To  the  combined  filtrate  from  the  A12O3  +  Fe2O3 
precipitate  a  few  drops  of  NH4OH  are  added,  and  the  solution  brought 
to  boiling.  To  the  boiling  solution  20  cubic  centimeters  of  a  saturated 
solution  of  ammonium  oxalate  are  added,  and  the  boiling  continued 
until  the  precipitated  CaCaCX  assumes  a  well-defined  granular  form. 
It  is  then  allowed  to  stand  for  20  minutes,  or  until  the  precipitate  has 
settled,  and  then  filtered  and  washed.  The  precipitate  and  filter  are 
placed  wet  in  a  platinum  crucible,  and  the  paper  burned  off  over  a 
small  flame  of  a  Bunsen  burner.  It  is  then  ignited,  redissolved  in 
HC1,  and  the  solution  made  up  to  100  cubic  centimeters  with  water. 

1  This  precipitate  contains  TiO2,  P2O5,  Mn3O4. 

*  This  correction  of  A12O3  Fe2O3  for  silica  should  not  be  made  when  the  HF1  cor- 
rection of  the  main  silica  has  been  omitted,  unless  that  silica  was  obtained  by  only  one 
evaporation  and  nitration.  After  two  evaporations  and  nitrations  i  to  2  mg.  of  SiO 
are  still  to  be  found  with  the  A12O3  Fe2O3. 

3  In  this  way  only  is  the  influence  of  titanium  to  be  avoided  and  a  correct  result 
obtained  for  iron. 


272 

Ammonia  is  added  in  slight  excess,  and  the  liquid  is  boiled.  If  a  small 
amount  of  A12O3  separates  this  is  filtered  out,  weighed,  and  the  amount 
added  to  that  found  in  the  first  determination,  when  greater  accuracy 
is  desired.  The  lime  is  then  reprecipitated  by  ammonium  oxalate, 
allowed  to  stand  until  settled,  filtered  and  washed,1  weighed  as  oxide 
by  ignition  and  blasting  in  a  covered  crucible  to  constant  weight,  or 
determined  with  dilute  standard  permanganate.2 

Magnesia  (MgO). — The  combined  filtrates  from  the  calcium  pre- 
cipitates are  acidified  with  HC1  and  concentrated  on  the  steam  bath  to 
about  150  cubic  centimeters,  10  cubic  centimeters  of  saturated  solution 
of  Na(NH4)HPO4  are  added,  and  the  solution  boiled  for  several 
minutes.  It  is  then  removed  from  the  flame  and  cooled  by  placing 
the  beaker  in  ice  water.  After  cooling,  NH4OH  is  added  drop  by 
drop  with  constant  stirring  until  the  crystalline  ammonium-magnesium 
orthophosphate  begins  to  form,  and  then  in  moderate  excess,  the 
stirring  being  continued  for  several  minutes.  It  is  then  set  aside  for 
several  hours  in  a  cool  atmosphere  and  filtered.  The  precipitate  is 
redissolved  in  hot  dilute  HC1,  the  solution  made  up  to  about  100 
cubic  centimeters,  I  cubic  centimeter  of  a  saturated  solution  of 
Na(NH4)HPO4  added,  and  ammonia  drop  by  drop,  with  constant 
stirring  until  the  precipitate  is  again  formed  as  described  and  the 
ammonia  is  in  moderate  excess.  It  is  then  allowed  to  stand  for  about 
2  hours,  when  it  is  filtered  on  a  paper  or  a  Gooch  crucible,  ignited, 
cooled  and  weighed  as  M^PaOi. 

Alkalies  (K20  and  A^a20). — For  the  determination  of  the  alkalies, 
the  well-known  method  of  Prof.  J.  Lawrence  Smith  is  to  be  followed, 
either  with  or  without  the  addition  of  CaCO3  with  NH4C1. 

Anhydrous  Sulphuric  Acid  (SOa), — One  gram  of  the  substance  is 
dissolved  in  15  cubic  centimeters  of  HC1,  filtered  and  residue  washed 
thoroughly.3 

The  solution  is  made  up  to  250  cubic  centimeters  in  a  beaker  and 
boiled.  To  the  boiling  solution  10  cubic  centimeters  of  a  saturated 
solution  of  BaCl2  is  added  slowly  drop  by  drop  from  a  pipette  and  the 
boiling  continued  until  the  precipitate  is  well  formed,  or  digestion  on 
the  steam  bath  may  be  substituted  for  the  boiling.  It  is  then  set  aside 
over  night,  or  for  a  few  hours,  filtered,  ignited  and  weighed  as  BaSCX. 

Total  Sulphur. — One  gram  of  the  material  is  weighed  out  in  a 
large  platinum  crucible  and  fused  with  Na2COs  and  a  little  KNO3, 
being  careful  to  avoid  contamination  from  sulphur  in  the  gases  from 
source  of  heat.  This  may  be  done  by  fitting  the  crucible  in  a  hole  in 

1  The  volume  of  wash-water  should  not  be  too  large;  vide  Hillebrand. 

-  The  accuracy  of  this  method  admits  of  criticism,  but  its  convenience  and  rapidity 
demand  its  insertion. 

3  Evaporation  to  dryness  is  unnecessary,  unless  gelatinous  silica  should  have  sep- 
arated and  should  never  be  performed  on  a  bath  heated  by  gas;  vide  Hillebrand. 


273 

an  asbestos  board.  The  melt  is  treated  in  the  crucible  with  boiling 
water  and  the  liquid  poured  into  a  tall  narrow  beaker  and  more  hot 
water  added  until  the  mass  is  disintegrated.  The  solution  is  then 
filtered.  The  filtrate  contained  in  a  No.  4  beaker  is  to  be  acidulated 
with  HC1  and  made  up  to  250  cubic  centimeters  with  distilled  water, 
boiled,  the  sulphur  precipitated  as  BaSO*  and  allowed  to  stand  over 
night  or  for  a  few  hours. 

Loss  on  Ignition. — Half  a  gram  of  cement  is  to  be  weighed  out 
in  a  platinum  crucible,  placed  in  a  hole  in  an  asbestos  board  so  that 
about  three-fifths  of  the  crucible  projects  below,  and  blasted  15  min- 
utes, preferably  with  an  inclined  flame.  The  loss  by  weight,  which  is 
checked  by  a  second  blasting  of  5  minutes,  is  the  loss  on  ignition. 

May,  1903 :  Recent  investigations  have  shown  that  large  errors 
in  results  are  often  due  to  the  use  of  impure  distilled  water  and 
reagents.  The  analyst  should,  therefore,  test  his  distilled  water  by 
evaporation  and  his  reagents  by  appropriate  tests  before  proceeding 
with  his  work. 

STEEL. 

METHODS  OF  CHEMICAL  ANALYSIS  FOR  PLAIN  CARBON  STEEL, 

AS  PUBLISHED  BY  THE  AMERICAN  SOCIETY 

FOR  TESTING  MATERIAL. 

ADOPTED,  1914. 

DETERMINATION  OF  CARBON  BY  THE 
DlRECT-COMBUSTION  METHOD. 

The  method  of  direct  combustion  of  the  metal  in  oxygen 
is  recommended,  the  carbon  dioxide  obtained  being  absorbed 
in  barium-hydroxide  solution,  the  precipitated  barium  carbon- 
ate filtered  off,  washed,  dissolved  in  a  measured  excess  of 
hydrochloric  acid  and  the  excess  titrated  against  standard 
alkali. 

The  use  of  potassium-hydroxide  solution  or  soda  lime  for 
the  absorption  of  carbon  dioxide,  with  suitable  purifying  train 
following  the  furnace,  is  recognized  as  being  capable  of  very 
satisfactory  refinement  and  as  possessing  merit  where  the  time 
element  is  of  prime  significance. 

Owing  to  the  diversity  of  apparatus  by  which  correct  results 
may  be  obtained  in  the  determination  of  carbon,  the  recom- 


274 

mendations  are  intended  more  to  indicate  what  is  acceptable 
than  to  prescribe  definitely  what  shall  be  used. 

Apparatus. 

Purifying  Train. — The  method  employed  eliminates  the 
necessity  of  a  purifying  train  following  the  furnace,  inasmuch 
as  no  precautions  are  necessary  to  prevent  access  of  water 
vapor,  or  sulphur  trioxide — the  impurities  usually  guarded 
against — from  the  absorbing  apparatus.  All  that  is  needed  is 
a  calcium-chloride  tower  filled  with  stick  sodium  hydroxide 
placed  before  the  furnace,  or  between  the  furnace  and  cata- 
lyzer, if,  as  recommended,  the  latter  is  used  for  the  purpose 
of  oxidizing  organic  matter  in  the  oxygen. 

Material  for  Lining  Boats. — Alundum,  "RR  Alundum,  al- 
kali-free, specially  prepared  for  carbon  determination,"  as  sup- 
plied by  dealers  is  suitable,  and  is  recommended.  The  90- 
mesh  or  finer  grades  are  used.  Chromite,  properly  sized  and 
freed  from  materials  causing  a  blank,  may  also  be  employed. 
No  substance  containing  alkali  or  alkaline  earth  metals,  or  car- 
bon as  carbonates  or  in  other  form,  should  be  used  as  a  lining 
material.  Quartz  sand,  owing  to  its  liability  to  fuse  or  to  slag 
with  the  oxides  of  iron,  causing  bubbles  of  gas  to  be  enclosed, 
is  objectionable.  Aluminum  oxide,  made  by  calcining  alum  or 
otherwise,  often  contains  sulphate  not  easily  destroyed,  or  may 
contain  objectionable  substances  of  an  alkaline  nature. 

Catalyzers. — Suitable  catalyzers  are  copper  oxide,  platinized 
quartz  or  asbestos,  or  platinum  gauze.  One  of  these  should  be 
used  in  the  forward  part  of  the  combustion  apparatus,  as  well 
as  in  the  purifying  train  preceding  the  combustion  tube  (see 
above).  Platinized  materials  sometimes  give  off  volatile  sub- 
stances on  heating,  and  whatever  material  is  used  should  not 
be  subject  to  this  defect. 

Combustion  Apparatus. — Any  apparatus  heated  by  gas  or 
electricity  which  will  bring  the  sample  to  a  temperature  of  950 
to  1,100°  C.  may  be  used.  Combustion  tubes  may  be  porce- 
lain, glazed  on  one  or  both  sides,  quartz  or  platinum.  Quartz 
is  liable  to  devitrification  when  used  continuously  at  tempera- 


275 


tures  above  1,000°  C.,  and  may  then  become  porous.  Com- 
bustion crucibles  of  platinum  may  be  heated  by  blast  or  by 
Meker  burners. 

Boats  or  Other  Containers  of  Samples  being  Burned. — 
These  may  be  of  porcelain,  quartz,  alundum,  clay,  platinum, 
or  nickel,  and  should  always  receive  a  lining  of  granular  alun- 
dum. 

Purifying  Train  before  Combustion  Apparatus. — This  con- 
sists of  a  tower  filled  with  stick  sodium  hydroxide,  preceded  by 
a  catalyzer. 

The  Train  after  the  Combustion  Apparatus. — This  consists 
merely  of  the  Meyer  tube  for  absorption  of  the  carbon  dioxide, 
protected  by  a  soda-lime  tube  at  the  far  end.  Meyer  tubes 
with  7  to  10  bulbs  of  10  to  15  cubic  centimeter  capacity  each, 
and  large  bulbs  at  the  ends,  having  volumes  equal  to  the  com- 
bined capacity  of  the  small  bulbs,  have  been  used  and  found 
satisfactory. 


FIG.  70.— Apparatus  for  Filtration  in  Determination  of  Carbon  by  the 
Direct-Combustion  Method. 

Filtering  Apparatus. — In  filtration  for  accurate  work,  care 
should  be  taken  to  protect  the  solution  from  access  of  extra- 
neous carbon  dioxide.  This  is  accomplished  in  the  apparatus 
shown  in  Fig.  70.  For  work  requiring  less  accuracy,  the  barium 


276 

carbonate  may  be  filtered  off  on  a  filter  made  by  fitting  a  car- 
bon funnel  with  a  perforated  porcelain  disk  and  filtering  by 
suction.  The  precipitate  is  then  washed  with  distilled  water 
from  which  the  carbon  dioxide  has  been  removed  by  boiling. 

Reagents. 

Oxygen. — Oxygen  of  not  less  than  97  per  cent,  purity  is 
recommended.  Endeavor  should  be  made  to  obtain  oxygen 
which  gives  no  blank,  since  the  correction  for  or  elimination  of 
this  is  troublesome  and  uncertain.  For  the  most  accurate 
work,  particularly  with  low-carbon  products,  such  as  ingot 
iron,  etc.,  the  blank  should  be  completely  eliminated  by  the  use 
of  a  catalyzer  before  the  furnace,  with  a  carbon-dioxide  ab- 
sorbent interposed  between  furnace  and  catalyzer. 

Tenth-normal  Hydrochloric  Acid. — This  may  be  standard- 
ized by  any  of  the  accepted  methods,  or  as  follows :  Twenty 
cubic  centimeters  of  the  approximately  N/io  acid  is  measured 
out  with  a  pipette,  and  the  silver  chloride  precipitated  by  an 
excess  of  silver-nitrate  solution  in  a  volume  of  50  to  60  cubic 
centimeters.  After  digesting  at  70  to  80°  C.,  until  the  super- 
natant liquid  is  clear,  the  chloride  is  filtered  off  on  a  tared 
Gooch  filter  and  washed  with  water  containing  2  cubic  centi- 
meters of  nitric  acid  per  100  cubic  centimeters  of  water  until 
freed  from  silver  nitrate.  After  drying  to  constant  weight 
at  130°  C.,  the  increase  of  weight  over  the  original  tare  is 
noted  and  from  this  weight,  corresponding  to  the  silver  chlo- 
ride, the  strength  of  the  hydrochloric  acid  is  calculated,  after 
which  it  is  adjusted  to  the  strength  prescribed.  The  standard- 
ization should  be  based  upon  several  concordant  determinations 
using  varying  amounts  of  acid. 

i  cc.  N/io  HC1  =  0.0006  g.  carbon. 

Methyl  Orange. — Dissolve  0.02  gram  in  100  cubic  centi- 
meters of  hot  distilled  water  and  filter. 

Tenth-normal  Sodium-Hydroxide  Solution. — This  is  stand- 
ardized against  the  hydrochloric  acid.  Methyl  orange  is  used 
as  the  indicator.  The  sodium-hydroxide  solution  should  be 
stored  in  a  large  bottle  from  which  it  may  be  driven  out  by  air 


277 

pressure,  protecting  against  carbon  dioxide  by  soda-lime  tubes. 
Barium-Hydroxide  Solution. — A  saturated  solution  is  fil- 
tered and  stored  in  a  large  reservoir  from  which  it  is  delivered 
by  air  pressure,  protecting  from  carbon  dioxide  by  a  soda-lime 
tube.  Three  or  four  small  bulbs  of  the  Meyer  tube  are  filled, 
and  CO2-free  water  is  added  until  the  remaining  small  bulbs 
are  filled. 

Factors  Influencing  Rapid  Combustion. 

Size  of  Particles  of  Sample. — The  finer  the  chips  the  better, 
except  with  samples  which  burn  too  vigorously  (see  under 
"Rate  of  Admitting  Oxygen").  Particles  too  coarse  to  pass 
a  2O-mesh  sieve  are  not  recommended,  nor  long  curly  drillings 
which  will  not  pack  closely.  A  ^-inch  flat  drill  may  be  used 
for  taking  the  sample  and  the  pressure  and  speed  of  the  drill- 
press  regulated  to  secure  the  desired  result ;  or,  better  still,  the 
sample  may  be  obtained  with  a  small  milling  machine  suitable 
for  sampling,  or  by  a  shaping  machine.  Oil,  dust,  and  other 
foreign  matter  should  be  carefully  excluded. 

Manner  of  Distributing  Sample  in  Boat. — This  is  of  con- 
siderable importance.  With  all  samples,  close  packing  in  a 
small  space  is  conducive  to  rapid  combustion.  In  the  case  of 
samples  which  burn  too  vigorously,  a  satisfactory  regulation 
may  sometimes  be  attained  by  spreading  the  sample  loosely 
over  the  lining  in  the  boat. 

Rate  of  Admitting  Oxygen. — The  rate  at  which  oxygen  is 
admitted  is  also  a  factor  in  the  velocity  of  combustion.  Assum- 
ing the  combustion  apparatus  to  be  heated  to  the  temperature 
range  recommended  above  (950  to  1,100°  C.),  it  is  possible,  if 
the  material  is  closely  packed  and  if  oxygen  is  admitted  at  too 
rapid  a  rate,  that  the  combustion  may  be  so  violent  as  to  cause 
excessive  spattering  of  fused  oxides,  and  such  fluidity  of  the 
molten  slag  that  the  boat  or  other  container  may  be  injured  or 
destroyed;  therefore  a  moderate  rate  of  burning  is  to  be 
sought.  This  is  desirable  also  from  the  standpoint  of  the  com- 
plete absorption  of  the  carbon  dioxide  by  the  barium-hydroxide 
solution.  The  factors,  temperature  of  combustion  apparatus, 


278 

manner  of  distribution  of  sample,  and  rate  of  admission  of 
oxygen,  can  be  governed  so  as  to  burn  successfully  steels  of  a 
very  wide  range  of  compositions,  in  either  fine  or  coarse 
particles. 

Method. 

After  having  properly  set  up  and  tested  the  apparatus,  place 
2  grams  of  steel  (see  note  No.  i)  in  the  form  recommended 
above,  in  a  moderately  packed  condition  on  the  bed  material 
and  introduce  the  boat  into  the  combustion  apparatus,  already 
heated  to  the  proper  temperature.  After  about  a  minute  (to 
allow  the  sample  and  container  to  reach  the  temperature  of  the 
furnace),  admit  oxygen  somewhat  more  rapidly  than  it  is  con- 
sumed, as  shown  by  the  rate  of  bubbling  in  the  Meyer  tube  (see 
note  No.  2).  The  sample  burns  completely  in  i  or  2  minutes, 
and  all  that  is  now  necessary  is  to  sweep  all  the  carbon  dioxide 
into  the  absorption  apparatus.  This  can  be  accomplished  in 
6  to  8  minutes  by  passing  about  i  or  2  liters  of  oxygen.  De- 
tach the  Meyer  tube  (see  note  No.  2)  and  filter  and  wash  the 
barium  carbonate,  using  the  special  filtering  apparatus  shown. 
After  solution  in  a  measured  excess  of  hydrochloric  acid  (the 
Meyer  tube  being  washed  out  with  a  portion  of  the  acid,  to 
remove  adhering  barium  carbonate),  titrate  the  excess  of  acid 
against  alkali  and  from  the  data  thus  obtained  calculate  the 
percentage  of  carbon. 

NOTES. 

1.  When  working  with  steels  high  in  carbon   (above  I  per  cent.) 
it  is  advisable  not  to  use  more  than  I  gram  in  order  that  nitration  may 
be  sufficiently  rapid. 

2.  As  a  precaution  against  error  resulting  from  too  rapid  passage 
of  the  gases,  it  is  well  to  attach  a  second  barium-hydroxide  tube  to 
retain  any  carbon  dioxide  that  may  pass  the  first. 

3.  For  the  most  accurate  work  the  Meyer  tubes  should  be  washed 
with  dilute  acid  before  beginning  work  each  day.    After  a  determina- 
tion is  finished  the  tube  should  be  completely  filled  two  or  three  times 
with  tap  water,  then  rinsed  with  distilled  water,  in  order  to  remove 
the  carbon  dioxide  liberated  when  dissolving  the  carbonate  from  the 
previous  determination. 


279 

4.  The  flask  containing  the  carbonate  should  be  thoroughly  agi- 
tated after  adding  the  acid,  since  the  carbonate  sometimes  dissolves 
rather  slowly  if  this  is  not  done ;  this  is  particularly  the  case  if  it  has 
packed  much  during  nitration. 

Apparatus  and  Procedure  for.  Filtration. 

The  apparatus  is  shown  to  approximately  one-tenth  size  in 
Fig.  70,  which  is  self-explanatory.  The  stop-cock  is  a  three- 
way  cock  connected  to  the  suction  pipe.  The  rubber  tubing 
connected  to  the  Meyer  tube  should  be  of  best-grade  black 
rubber,  and  the  lengths  used  should  be  so  chosen  as  to  permit 
of  easy  manipulation  of  the  tube.  The  Meyer  tube  is  con- 
nected or  disconnected  by  the  rubber  stoppers  which  are  left 
always  attached  to  the  rubber  tubes.  The  carbon  tube  C  is 
fitted  with  a  perforated  porcelain  plate  sliding  easily. 

The  funnel  is  prepared  for  filtration  by  making  on  the  por- 
celain disk  a  felt  of  asbestos  about  1/16  to  1/8  inch  in  thickness, 
using  amphibole  (not  serpentine)  asbestos  which  has  been 
carefully  digested  with  strong  hydrochloric  acid  for  several 
hours  and  washed  with  water  until  it  gives  no  acid  reaction. 
On  top  of  the  asbestos  pad  is  placed  a  layer  of  similarly  treated 
quartz,  mixed  with  asbestos,  of  the  height  shown.  A  mixture 
of  quartz  grains  of  various  sizes  (approximately  50  per  cent, 
passing  a  2O-mesh  sieve  and  50  per  cent,  passing  a  lo-mesh  and 
remaining  on  a  2O-mesh  sieve)  is  suitable.  The  mixture  of 
quartz  and  asbestos  may  be  obtained  by  filling  the  funnel  from 
a  beaker  (directing  against  it  a  stream  from  a  wash-bottle) 
while  maintaining  a  gentle  suction.  In  this  way  the  asbestos 
is  properly  mixed  with  the  quartz.  A  little  experience  and 
attention  to  these  details  will  enable  one  to  prepare  the  quartz- 
bed  in  a  manner  that  will  greatly  expedite  filtration.  The 
stopper  is  now  inserted  in  the  funnel,  the  Meyer  tube  connected 
as  shown  and  the  liquid  and  precipitate  sucked  into  the  funnel. 
Only  a  gentle  suction  should  be  used.  When  necessary  P3  is 
opened  to  admit  air  back  of  the  column  of  liquid  in  the  Meyer 
tube.  When  the  contents  of  the  Meyer  tube  have  been  trans- 
ferred, the  large  bulb  nearest  B  is  half  filled  with  water  by  open- 
ing PI  ;  the  stop-cock  $  is  operated  during  this  and  subsequent 


2&D 


operations  so  as  to  maintain  a  gentle  suction  all  the  time.  M 
is  now  manipulated  so  as  to  bring  the  wash  water  in  contact 
with  all  parts  of  the  interior,  after  which  the  water  is  sucked 
through  C;  P2  is  left  open  during  this  and  subsequent  wash- 
ings. After  eight  washings  as  directed,  allowing  the  wash 
water  to  drain  off  thoroughly  each  time  before  adding  more, 
M  may  be  detached,  the  stopper  removed  from  the  funnel  and 
the  washings  completed  by  filling  C  to  the  top  with  CO2-free 
water,  sucking  off  completely  and  repeating  the  operation  once. 
With  care  the  washing  may  be  done  with  150  cubic  centimeters 
of  water.  Air  is  now  admitted  through  the  side  opening  of  $, 
C  is  removed  and  the  porcelain  disk  carrying  the  asbestos, 
quartz  and  barium  carbonate  is  thrust,  by  means  of  a  long  glass 
rod,  into  a  flask,  removing  any  adhering  particles  from  the 
sides  of  C,  by  a  stream  of  water  from  a  wash  bottle.  An  ex- 
cess of  the  standard  acid  is  now  added  from  a  burette  or 
pipette,  using  a  portion  to  wash  out  M,  and  after  the  contents 
of  the  flask  have  been  thoroughly  agitated  by  shaking,  the  ex- 
cess of  acid  is  titrated  against  the  standard  alkali,  using  3 
drops  of  the  methyl-orange  indicator. 

NOTES. 

The  operation  of  filtering  can  be  carried  out  very  rapidly  after  a 
little  practice. 

Glass  wool  should  on  no  account  be  used  as  a  substitute  for  the 
quartz,  on  account  of  the  probability  of  errors  arising  from  its  attack 
by  the  alkali  or  acid. 

It  is  well  to  wash  out  the  rubber  tubes  connected  to  the  Meyer 
tube  with  a  little  water  each  day  before  beginning  work. 


DETERMINATION  OF  CARBON  BY  THE  COLORIMETRIC  METHOD. 

(Routine.) 
Solution  Required. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 


28l 


Method. 

In  a  small  Erlenmeyer  flask  or  test  tube,  dissolve  0.2  to  0.5 
gram  of  steel,  depending  on  the  carbon  content  of  the  sample, 
in  5  to  20  cubic  centimeters  of  the  nitric  acid.  Boil  gently 
until  the  solution  is  complete  and  the  liquid  is  clear.  Cool  and 
compare  with  a  solution  of  a  standard  steel  treated  under  like 
conditions. 

NOTE. 

In  order  to  obtain  reliable  results  by  this  method  the  standard 
steel  should  be  of  the  same  kind,  of  approximately  the  same  chemical 
composition,  and  in  the  same  physical  condition  as  the  sample  steel. 
The  carbon  content  of  the  standard  steel  is  determined  by  the  direct 
combustion  method. 

DETERMINATION  OF  MANGANESE  BY  THE 
BISMUTHATE  METHOD. 

Solutions  Required. 

Nitric  Acid. — Mix  500  cubic  centimeters  of  nitric  acid,  spe- 
cific gravity  1.42,  and  1,500  cubic  centimeters  of  distilled  water. 

Nitric  Acid  for  Washing. — Mix  30  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  970  cubic  centimeters  of 
distilled  water. 

Stock  Sodium  Arsenite. — To  15  grams  of  arsenious  acid 
(As2O3)  in  a  300  cubic  centimeter  Erlenmeyer  flask,  add  45 
grams  of  sodium  carbonate  and  150  cubic  centimeters  of  dis- 
tilled water.  Heat  the  flask  and  contents  on  a  water  bath 
until  the  arsenious  acid  is  dissolved,  cool  the  solution  and  make 
up  to  1,000  cubic  centimeters  with  distilled  water. 

Standard  Sodium  Arsenite. — Dilute  300  cubic  centimeters  of 
stock-sodium-arsenite  solution  to  1,000  cubic  centimeters  with 
distilled  water  and  titrate  against  potassium  permanganate 
solution  (about  N/io),  which  has  been  standardized  by  using 
Bureau  of  Standards  sodium  oxalate.1  Adjust  the  solution  so 
that  i  cubic  centimeter  is  equivalent  to  o.io  per  cent,  of  man- 
ganese, when  a  i-gram  sample  is  taken. 

i  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


282 

The  factor  Na2C2O4  »~*  Mil  =  0.16397  (using  the  1913 
atomic  weights). 

Method. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  I  gram 
of  steel  in  50  cubic  centimeters  of  the  nitric  acid,  and  boil  to 
expel  the  oxides  of  nitrogen.  Cool,  and  add  about  T/2  gram  of 
sodium  bismuthate  and  heat  for  a  few  minutes,  or  until  the 
pink  color  has  disappeared,  with  or  without  precipitation  of 
manganese  dioxide.  Add  small  portions  of  ferrous  sulphate 
(or  any  suitable  reducing  agent)  in  sufficient  quantity  to  clear 
the  solution,  and  boil  to  expel  the  oxides  of  nitrogen.  Cool  to 
15°  C.,  add  an  excess  of  sodium  bismuthate  and  agitate  for  a 
few  minutes.  Add  50  cubic  centimeters  of  3  per  cent,  nitric 
acid  and  filter  through  an  alundum  filter  or  asbestos  pad,  wash- 
ing with  3  per  cent,  nitric  acid.  Titrate  immediately  with 
standard-sodium-arsenite  solution  to  the  disappearance  of  the 
pink  color,  each  cubic  centimeter  required  representing  o.io 
per  cent,  manganese. 

NOTES. 

In  the  method,  the  preliminary  treatment  with  sodium  bismuthate 
has  been  found  by  a  number  of  investigators  to  be  apparently  unneces- 
sary; however,  the  available  data  to  confirm  this  position  are  not  con- 
sidered sufficient  to  warrant  its  omission. 

In  making  the  asbestos  filter  pad  it  is  advisable  to  have  a  thin  bed, 
and  as  much  surface  as  possible.  This  insures  rapid  filtration,  and 
the  filter  may  be  used  until  it  becomes  clogged  with  bismuthate. 

The  filtrate  must  be  perfectly  clear,  since  the  least  particle  of 
bismuthate  carried  through  the  filter  will  vitiate  the  results. 

DETERMINATION  OF  MANGANESE  BY  THE 

PERSULPHATE  METHOD. 

(Routine.) 

Solutions  Required. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 


283 

Silver  Nitrate. — Dissolve  1.33  grams  of  silver  nitrate  in 
1,000  cubic  centimeters  of  distilled  water. 

Stock  Sodium  Arsenite. — To  15  grams  of  arsenious  acid 
(As2O3)  in  a  300  cubic  centimeter  Erlenmeyer  flask,  add  45 
grams  of  sodium  carbonate  and  150  cubic  centimeters  of  dis- 
tilled water.  Heat  the  flask  and  contents  on  a  water  bath 
until  the  arsenious  acid  is  dissolved,  cool  the  solution  and  make 
up  to  1,000  cubic  centimeters  with  distilled  water. 

Standard  Sodium  Arsenite. — Dilute  a  sufficient  quantity  of 
stock-sodium-arsenite  solution  with  distilled  water,  and  stand- 
ardize against  a  steel  of  known  manganese  content,  as  deter- 
mined by  the  bismuthate  method.  This  solution  should  be  of 
such  strength  that  each  cubic  centimeter  will  be  equivalent  to 
o.io  per  cent,  of  manganese  on  the  basis  of  the  weight  of 
sample  taken. 

Method. 

In  a  small  Erlenmeyer  flask  or  large  test  tube,  dissolve  o.i 
to  0.3  gram  of  steel,  depending  on  the  manganese  content  of 
the  sample,  in  15  cubic  centimeters  of  the  nitric  acid.  Boil  gen- 
tly until  the  solution  is  complete  and  the  liquid  is  clear.  Add  15 
cubic  centimeters  silver  nitrate  solution  and  I  gram  of  am- 
monium persulphate,  and  continue  heating  the  solution  for 
T/2  minute  after  the  oxidation  begins  and  bubbles  rise  freely. 
Cool  in  running  water  and  complete  the  determination  by  either 
of  the  following  procedures : 

(a)  C olorimetric . — Compare  the  color  of  the  solution  with 
that  of  a  standard  steel  treated  under  like  conditions. 

(b)  Titration. — Titrate  with  standard-sodium-arsenite  solu- 
tion to  the  disappearance  of  the  pink  color,  each  cubic  centi- 
meter required  representing  o.io  per  cent,  of  manganese. 

NOTES. 

In  order  to  obtain  reliable  results  by  the  colorimetric  procedure, 
the  standard  should  be  of  the  same  kind  and  of  approximately  the 
same  chemical  composition  as  the  sample  steel.  The  manganese  con- 
tent of  the  standard  steel  is  determined  by  the  bismuthate  method. 

The  ammonium  persulphate  should  be  kept  in  moistened  condition 
by  small  additions  ot"  distilled  water  at  required  intervals. 


284 

DETERMINATION  OF  PHOSPHORUS  BY  THE 

MoiyYBDATE-MAGNESIA    METHOD. 

Solutions  Required. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  20  cubic  centimeters  nitric 
acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters  of  dis- 
tilled water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Bisulphite. — Dissolve  30  grams  of  ammonium 
bisulphite  in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Hydroxide,  approximately  10  per  cent. — Mix 
1,000  cubic  centimeters  of  ammonium  hydroxide,  specific  grav- 
ity 0.90,  and  2,000  cubic  centimeters  of  distilled  water. 

Ammonium  Molybdate — Solution  No.  i. — Place  in  a  beaker 
100  grams  of  85  per  cent,  molybdic  acid,  mix  it  thoroughly 
with  240  cubic  centimeters  of  distilled  water,  add  140  cubic 
centimeters  of  ammonium  hydroxide,  specific  gravity  0.90, 
filter,  and  add  60  cubic  centimeters  of  nitric  acid,  specific 
gravity  1.42. 

Solution  No.  2. — Mix  400  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  960  cubic  centimeters  of  distilled 
water. 

When  the  solutions  are  cold,  add  solution  No.  I  to  solution 
No.  2,  stirring  constantly;  then  add  o.i  gram  of  ammonium 
phosphate  dissolved  in  10  cubic  centimeters  of  distilled  water, 
and  let  stand  at  least  24  hours  before  using. 

Magnesia  Mixture. — Dissolve  50  grams  of  magnesium  chlo- 
ride and  125  grams  of  ammonium  chloride  in  750  cubic  centi- 
meters of  distilled  water,  and  then  add  150  cubic  centimeters  of 
ammonium  hydroxide,  specific  gravity  0.90. 

Method. 
In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  5  grams 


of  steel  in  75  cubic  centimeters  of  the  nitric  acid.  Heat  to 
boiling;  while  boiling  add  about  12  cubic  centimeters  of  the 
potassium-permanganate  solution,  and  continue  boiling  until 
manganese  dioxide  precipitates.  Dissolve  this  precipitate  by 
additions  of  the  ammonium  bisulphite  solution,  boil  until  clear 
and  free  from  brown  fumes,  cool  to  35°  C.,  add  100  cubic 
centimeters  of  the  ammonium-molybdate  solution  at  room  tem- 
perature, let  stand  I  minute,  shake  or  agitate  for  3  minutes, 
filter  on  a  9-centimeter  paper  and  wash  the  precipitate  at  least 
3  times  with  the  2  per  cent,  nitric-acid  solution  to  free  it  from 
iron. 

Treat  the  precipitate  on  the  filter  with  the  10  per  cent,  am- 
monium-hydroxide soluion,  letting  the  solution  run  into  a 
loo-cubic  centimeter  beaker  containing  10  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20,  and  0.5  gram  of  citric 
acid;  add  30  cubic  centimeters  of  ammonium  hydroxide,  spe- 
cific gravity  0.90,  cool,  and  then  add  10  cubic  centimeters  of  the 
magnesia  mixture  very  slowly,  while  stirring  the  solution 
vigorously.  Set  aside  in  a  cool  place  for  2  hours,  filter  and 
wash  with  the  10  per  cent,  ammonium  hydroxide  solution.  Ig- 
nite and  weigh.  Dissolve  the  precipitate  of  magnesium  pyro- 
phosphate  with  5  cubic  centimeters  of  nitric  acid,  specific 
gravity  1.20,  and  20  cubic  centimeters  of  distilled  water,  filter 
and  wash  with  hot  water.  Ignite  and  weigh.  The  difference 
in  weights  represents  pure  magnesium  pyrophosphate  contain- 
ing 27.84  per  cent,  of  phosphorus. 

NOTE. 

The  ammonium  molybdate  solution  should  be  kept  in  a  cool  place 
and  should  always  be  filtered  before  using. 

DETERMINATION  OF  PHOSPHORUS  BY  THE  Ai,  KALI  METRIC 
METHOD. 

(Routine.) 
Solutions  Required. 

Nitric  Acid. — Mix   1,000  cubic  centimeters  of  nitric  acid, 
19 


286 


specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  20  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters 
of  distilled  water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Bisulphite. — Dissolve  30  grams  of  ammonium 
bisulphite  in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Molybdate. — Solution  No.  i. — Place  in  a  beaker 
100  grams  of  85  per  cent,  molybdic  acid,  mix  it  thoroughly  with 
240  cubic  centimeters  of  distilled  water,  add  140  cubic  centi- 
meters of  ammonium  hydroxide,  specific  gravity  0.90,  filter  and 
add  60  cubic  centimet  ers  of  nitric  acid,  specific  gravity  1.42. 

Solution  No.  2. — Mix  400  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  960  cubic  centimeters  of  distilled 
water. 

When  the  solutions  are  cold,  add  solution  No.  I  to  solution 
No.  2,  stirring  constantly;  then  add  o.i  gram  of  ammonium 
phosphate  dissolved  in  10  cubic  centimeters  of  distilled  water 
and  let  stand  at  least  24  hours  before  using. 

Potassium  Nitrate,  I  per  cent. — Dissolve  10  grams  of  potas- 
sium nitrate  in  1,000  cubic  centimeters  of  distilled  water. 

Phenolphthalein  Indicator. — Dissolve  0.2  gram  in  50  cubic 
centimeters  of  95  per  cent,  ethyl  alcohol  and  50  cubic  centi- 
meters of  distilled  water. 

Standard  Sodium  Hydroxide. — Dissolve  6.5  grams  of  puri- 
fied sodium  hydroxide  in  1,000  cubic  centimeters  of  distilled 
water,  add  a  slight  excess  of  I  per  cent,  solution  of  barium 
hydroxide,  let  stand  for  24  hours,  decant  the  liquid,  and 
standardize  it  against  a  steel  of  known  phosphorus  content, 
as  determined  by  the  molybdate  magnesia  method,  so  that  I 
cubic  centimeter  will  be  equivalent  to  o.oi  per  cent,  of  phos- 
phorus on  the  basis  of  a  2-gram  sample  (see  notes).  Protect 
the  solution  from  carbon  dioxide  with  a  soda  lime  tube. 

Standard  Nitric  Acid. — Mix  10  cubic  centimeters  of  nitric 
acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters  of  dis- 


28; 

tilled  water.  Titrate  the  solution  against  standardized  sodium 
hydroxide,  using  phenolphthalein  as  indicator,  and  make  it 
equivalent  to  the  sodium  hydroxide  by  adding  distilled  water. 

Method. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  2  grams 
of  steel  in  50  cubic  centimeters  of  the  nitric  acid.  Heat  the 
solution  to  boiling  and  while  boiling  add  about  6  cubic  centi- 
meters of  the  potassium  permanganate  solution  and  continue 
boiling  until  manganese  dioxide  precipitates.  Dissolve  this 
precipitate  by  addition  of  the  ammonium  bisulphite  solution, 
boil  until  clear  and  free  from  brown  fumes,  cool  to  80°  C., 
add  50  cubic  centimeters  of  the  ammonium  molybdate  solu- 
tion at  room  temperature,  let  stand  I  minute,  shake  or  agitate 
for  3  minutes,  and  filter  on  a  9  centimeter  paper.  Wash 
the  precipitate  three  times  with  the  2  per  cent,  nitric  acid  solu- 
tion to  free  it  from  iron,  and  continue  the  washing  with  the  I 
per  cent  potassium  nitrate  solution  until  the  precipitate  and 
flask  are  free  from  acid. 

Transfer  the  paper  and  precipitate  to  a  solution  flask,  add 
20  cubic  centimeters  of  distilled  water,  5  drops  of  phenol- 
phthalein solution  as  indicator,  and  an  excess  of  standard 
sodium  hydroxide  solution.  Insert  a  rubber  stopper  and  shake 
vigorously  until  solution  of  the  precipitate  is  complete.  Wash 
off  the  stopper  with  distilled  water  and  determine  the  excess 
of  sodium  hydroxide  solution  by  titrating  with  standard  nitric 
acid  solution.  Each  cubic  centimeter  of  standard  sodium  hy- 
droxide solution  represents  o.oi  per  cent,  of  phosphorus. 

NOTES. 

The  ammonium  molybdate  solution  should  be  kept  in  a  cool  place 
and  should  always  be  filtered  before  using. 

All  distilled  water  used  in  titration  should  be  freed  from  carbon 
dioxide  by  boiling  or  otherwise. 

Bureau  of  Standards  Standard  Steel  No.  19  (a)  is  recommended 
as  a  suitable  steel  for  standardization  of  the  sodium  hydroxide  solution. 


288 

DETERMINATION  OF  SULPHUR  BY  THE;  OXIDATION  METHOD. 
Solution  Required. 

Barium  Chloride. — Dissolve  100  grams  of  barium  chloride 
in  1,000  cubic  centimeters  of  distilled  water. 

Method. 

In  a  400  cubic  centimeter  beaker  dissolve  5  grams  of  the 
steel  in  a  mixture  of  40  cubic  centimeters  of  nitric  acid,  spe- 
cific gravity  1.42,  and  5  cubic  centimeters  of  hydrochloric  acid, 
specific  gravity  1.20,  add  0.5  gram  of  sodium  carbonate  and 
evaporate  the  solution  to  dryness.  Add  40  cubic  centimeters 
of  hydrochloric  acid,  specific  gravity  1.20,  evaporate  to  dry- 
ness  and  bake  at  a  moderate  heat.  After  solution  of  the  resi- 
due in  30  cubic  centimeters  of  hydrochloric  acid,  specific  grav- 
ity i. 20,  and  evaporation  to  sirupy  consistency,  add  2  to  4 
cubic  centimeters  of  hydrochloric  acid,  specific  gravity  1.20, 
and  then  30  to  40  cubic  centimeters  of  hot  water.  Filter  and 
wash  with  cold  water,  the  final  volume  not  exceeding  100 
cubic  centimeters.  To  the  cold  filtrate  add  10  cubic  centi- 
meters of  the  barium  chloride  solution.  I^et  stand  at  least  24 
hours,  filter  on  a  9  centimeter  paper,  wash  the  precipi- 
tate first  with  a  hot  solution  containing  10  cubic  centimeters 
of  hydrochloric  acid,  specific  gravity  1.20,  and  I  gram  barium 
chloride  to  the  liter,  until  free  from  iron;  and  then  with  hot 
water  till  free  from  chloride.  Ignite  and  weigh  as  barium 
sulphate. 

Keep  the  washings  separate  from  the  main  filtrate  and 
evaporate  them  to  recover  any  dissolved  barium  sulphate. 

NOTE. 

A  blank  determination  on  all  reagents  used  should  be  made  and 
the  results  corrected  accordingly. 

DETERMINATION  OF  SULPHUR  BY  THE  EVOUJTION-TITRATION 

METHOD. 

(Routine.) 

Apparatus. 

Use  a  480  cubic  centimeter  flask  with  a  delivery  tube  and  a 
300  cubic  centimeter  tumbler  of  tall  form  (Fig.  71). 


289 


Capacity 
IB  02. 


1 

1 

1 

1 

1   w  , 

c  c. 

^^^ 

Ir^F  "^ 

1  ~ 
~r 

r^r  "i 

t- 
i 

— 

L_ 

\         V 

FIG.  71 . —Apparatus  for  Determination  of  Sulphur  by  the  Evolution  Method. 

Solutions  Required. 

Dilute  Hydrochloric  Acid. — Mix  500  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20,  and  500  cubic  centi- 
meters of  distilled  water. 

Ammoniacal  Cadmium  Chloride. — Dissolve  10  grams  of 
cadmium  chloride  in  400  cubic  centimeters  of  distilled  water 
and  add  600  cubic  centimeters  of  ammonium  hydroxide,  spe- 
cific gravity  0.90. 

Potassium  lodate. — Dissolve  1.116  grams  of  potassium 
iodate  and  12  grams  of  potassium  iodide  in  1,000  cubic  centi- 
meters of  distilled  water.  Standardize  with  a  steel  of  known 
sulphur  content.  Each  cubic  centimeter  should  be  equivalent 
to  o.oi  per  cent,  of  sulphur,  when  a  5  gram  sample  is  used 
(see  notes). 


290 


Starch. — To  1,000  cubic  centimeters  of  boiling  distilled 
water,  add  a  cold  suspension  of  6  grams  of  starch  in  100 
cubic  centimeters  of  distilled  water;  cool,  add  a  solution  of 
6  grams  of  zinc  chloride  in  50  cubic  centimeters  of  distilled 
water,  and  mix  thoroughly. 

Method. 

Place  5  grams  of  steel  in  the  flask  and  connect  the  latter  as 
shown  in  Fig.  62.  Place  10  cubic  centimeters  of  the  ammoniacal 


FIG.  72. 

cadmium  chloride  solution  and  150  cubic  centimeters  of  dis- 
tilled water  in  the  tumbler.  Add  80  cubic  centimeters  of  the 
dilute  hydrochloric  acid  to  the  flask  through  the  thistle  tube, 
heat  the  flask  with  its  contents  gently  until  the  solution  of  the 
steel  is  complete,  then  boil  the  solution  for  y2  minute.  Re- 


move  the  tumbler  which  contains  all  the  sulphur  as  cadmium 
sulphide,  and  to  it  add  5  cubic  centimeters  of  starch  solution 
and  40  cubic  centimeters  of  the  dilute  hydrochloric  acid,  ti- 
trating immediately  with  potassium  iodate  solution  to  a  per- 
manent blue  color. 

NOTES. 

Extremely  slow  or  rapid  evolution  of  hydrogen  sulphide  is  to  be 
avoided. 

Bureau  of  Standards  Standard  Steel  No.  8  (a)  is  recommended 
for  standardizing  the  potassium  iodiate  solution. 


vS     /> 


FIG.  73. 


Editor's  Note. — Another  very  convenient  apparatus  is  shown  in 
Figs.  72  and  73.  It  can  be  heated  without  getting  the  cadmium  chloride 
solution  hot  while  heating  the  flask  containing  the  steel.  In  using  this 


292 

form,   10  cubic  centimeters   of  the  cadmium  solution  are  drawn  into 
the  tube,  Fig.  73,  without  diluting. 

After  all  the  H2S  has  been  driven  over,  the  tube  is  disconnected 
and  emptied  into  a  600  cubic  centimeter  beaker  by  pouring  it  out 
through  a.  The  tube  is  then  washed  by  filling  it  up  first  with  water, 
then  with  dilute  hydrochloric  acid,  and  again  with  water.  This  is 
best  accomplished  by  holding  the  nozzle  of  a  wash  bottle  against  b  and 
blowing  until  the  water  or  acid  reaches  the  top  of  the  tube.  Remove 
wash  bottle  and  empty  the  tube  into  beaker  as  above. 

DETERMINATION  OF  SILICON  BY  THE  NITRO-SULPHURIC 
METHOD. 

Solutions  Required. 

Nitro-Sulphuric  Acid. — Mix  1,000  cubic  centimeters  of  sul- 
phuric acid,  specific  gravity  1.84,  1,500  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  5,500  cubic  centimeters 
of  distilled  water. 

Dilute  Hydrochloric  Acid. — Mix  100  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20,  and  900  cubic  centi- 
meters of  distilled  water. 

Method. 

Add  cautiously  80  cubic  centimeters  of  the  nitro-sulphuric 
acid  to  4.702  grams  of  steel,  in  a  platinum  or  porcelain  dish 
of  300  cubic  centimeters  capacity,  cover  with  a  watch  glass, 
heat  until  the  steel  is  dissolved  and  evaporate  slowly  until 
copious  fumes  of  sulphuric  acid  are  evolved.  Cool,  add  125 
cubic  centimeters  of  distilled  water,  heat  with  frequent  stirring 
until  all  salts  are  dissolved,  add  5  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  heat  for  2  minutes,  and 
filter  on  a  9  centimeter  paper.  Wash  the  precipitate  several 
times  with  hot  water,  then  with  hydrochloric  acid  and  hot 
water  alternately  to  complete  the  removal  of  iron  salts, 
and  finally  with  hot  water  until  free  from  acid.  .Transfer  the 
filter  to  a  platinum  crucible,  burn  off  the  paper  carefully  with 
the  crucible  covered,  finally  igniting  over  a  blast  lamp  or  in  a 
muffle  furnace  at  1,000°  C.  for  at  least  20  minutes;  cool  in  a 


293 

desiccator  and  weigh.  Add  sufficient  sulphuric  acid,  specific 
gravity  1.84,  to  moisten  the  silica  and  then  a  small  amount  of 
hydrofluoric  acid.  Evaporate  to  dryness,  ignite  arid  weigh. 
The  difference  in  weights  in  milligrams  divided  by  100  equals 
the  percentage  of  silicon. 

NOTE. 

A  blank  determination  on  all  reagents  used  should  be  made  and 
the  results  corrected  accordingly. 

DETERMINATION  OF  SILICON  BY  THE  SULPHURIC  ACID 
METHOD. 

(Optional.) 
Solution  Required. 

Dilute  Hydrochloric  Acid. — Mix  100  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20,  and  900  cubic  centi- 
meters of  distilled  water. 

Method. 

To  2.351  grams  of  steel,  in  a  beaker  of  low  form  of  500 
cubic  centimeters  capacity,  add  60  cubic  centimeters  of  dis- 
tilled water,  and  then  cautiously  15  cubic  centimeters  of  sul- 
phuric acid,  specific  gravity  1.84.  Cover  with  a  watch  glass, 
heat  until  the  steel  is  dissolved  and  evaporate  until  copious 
fumes  of  sulphuric  acid  are  evolved.  Cool,  add  100  cubic 
centimeters  of  distilled  water  and  heat  with  frequent  stirring 
until  the  salts  are  in  solution.  Filter  on  a  9  centimeter  paper, 
wash  the  precipitate  several  times  with  cold  water,  then  with 
cold  dilute  hydrochloric  acid  until  free  from  iron,  and  finally 
with  cold  water  until  free  from  acid.  Ignite  and  weigh.  Add 
sufficient  sulphuric  acid,  specific  gravity  1.84,  to  moisten  the 
silica  and  then  a  small  amount  of  hydrofluoric  acid.  Evapo- 
rate to  dryness,  ignite  and  weigh.  The  difference  in  weights 
in  milligrams  divided  by  50  equals  the  percentage  of  silicon. 

NOTE. 

A  blank  determination  on  all  reagents  used  should  be  made  and 
the  results  corrected  accordingly. 


294 

DETERMINATION  OF  COPPER. 
Solutions  Required. 

Sulphuric  Acid. — Mix  200  cubic  centimeters  of  sulphuric 
acid  specific  gravity  X  1.84,  and  800  cubic  centimeters  of 
distilled  water. 

Potassium  Ferrocyanide. — Dissolve  10  grams  of  potassium 
ferrocyanide  in  100  cubic  centimeters  of  distilled  water. 

Standard  Copper  Nitrate. — Dissolve  2  grams  of  purest  elec- 
trolytic copper  in  20  cubic  centimeters  of  nitric  acid  (i  :  i), 
and  dilute  to  1,000  cubic  centimeters  with  distilled  water. 
Each  cubic  centimeter  is  equivalent  to  0.02  per  cent,  of  copper 
on  the  basis  of  a  10  gram  sample. 

Method. 

In  a  300  cubic  centimeter  beaker  dissolve  10  grams  of  the 
steel  in  75  cubic  centimeters  of  the  sulphuric  acid,  and  then 
add  150  cubic  centimeters  of  distilled  water.  Heat  the  solu- 
tion and  saturate  with  hydrogen  sulphide,  filter  and  wash  the 
precipitate  free  from  iron  with  i  per  cent,  sulphuric  acid  con- 
taining hydrogen  sulphide.  Incinerate  the  paper  with  its  con- 
tents in  a  porcelain  crucible  and  fuse  with  0.5  gram  of  acid 
sodium  sulphate.  Extract  with  hot  water,  filter,  and  complete 
the  determination  colorimetrically  as  under  i(a)  or  i(&),  or 
electrolytically  as  under  2,  as  follows : 

i.  Evaporate  the  filtrate  to  about  25  cubic  centimeters,  make 
faintly  ammoniacal,  filter  into  a  100  cubic  centimeter  Nessler 
tube  and  wash  with  hot  water. 

(a)  If  the  solution  is  a  strong  blue,  to  another  100  cubic 
centimeter  Nessler  tube  add  50  cubic  centimeters  of  distilled 
water,  5  cubic  centimeters  of  ammonium  hydroxide,  specific 
gravity  0.90,  and  from  a  burette  the  standard  copper  nitrate 
solution  until  the  blue  colors  match. 

(b)  If  the  solution  is  a  faint  blue,  to  the  filtrate  in  a  Nessler 
tube  add  the  dilute  sulphuric  acid  to  faint  acidity  and  then 
a  few  drops  of  the  potassium  ferrocyanide  solution.     To  an- 
other 100  cubic  centimeter  Nessler  tube  add  50  cubic  centi- 


295 

meters  of  distilled  water,  a  few  drops  of  the  potassium  ferro- 
cyanide  solution,  and  from  a  burette  the  standard  copper  ni- 
trate solution  until  the  reddish  brown  colors  match. 

2.  Make  the  nitrate  slightly  acid  with  sulphuric  acid,  dilute 
with  distilled  water  to  a  suitable  volume,  and  determine  the 
copper  electrolytically. 

DETERMINATION  OF  NICKEL  BY  THE  GRAVIMETRIC  DIMETHYI/- 
GLYOXIME  METHOD. 

Solutions  Required. 

Hydrochloric  Acid. — Mix  500  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity,  1.20,  and  500  cubic  centimeters 
of  distilled  water. 

Dimethylglyoxime. — Dissolve  I  gram  of  dimethylglyoxime 
in  100  cubic  centimeters  of  95  per  cent,  ethyl  alcohol. 

Method. 

In  a  150  cubic  centimeter  beaker  dissolve  I  gram  of  the 
steel  in  20  cubic  centimeters  of  the  hydrochloric  acid,  and 
add  about  2  cubic  centimeters  of  nitric  acid,  specific  gravity 
1.42,  to  oxidize  the  iron.  Filter  the  solution  and  add  to  the 
filtrate  6  grams  of  tartaric  acid,  and  water  till  the  volume  is 
300  cubic  centimeters.  Make  the  solution  faintly  ammoniacal, 
then  faintly  acid  with  the  hydrochloric  acid  and  heat  nearly 
to  boiling;  add  20  cubic  centimeters  of  the  dimethylglyoxime 
solution  and  then  ammonium  hydroxide,  specific  gravity  0.90, 
drop  by  drop  till  faintly  alkaline,  stirring  vigorously.  After 
standing  i  hour,  filter  on  a  weighed  Gooch  crucible,  wash  with 
hot  water,  dry  at  110°  to  120°  C.  and  weigh.  The  precipitate 
contains  20.31  per  cent,  of  nickel. 

NOTES. 

In  making  dimethylglyoxime  solution,  methyl  alcohol  may  be  sub- 
stituted for  ethyl  alcohol. 

The  weight  of  sample  taken  should  be  varied  according  to  the 
nickel  content. 


296 

DETERMINATION  OF  NlCKEX  BY  THE  VOLUMETRIC  DlMETHYI,- 

METHOD. 


(Routine.) 
Solutions  Required. 

Hydrochloric  Acid.  —  Mix  500  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  and  500  cubic  centimeters 
of  distilled  water. 

Dimethylglyoxime.  —  Dissolve  I  gram  of  dimethylglyoxime 
in  100  cubic  centimeters  of  95  per  cent,  ethyl  alcohol. 

Silver  Nitrate.  —  Dissolve  0.5  gram  of  silver  nitrate  in  1,000 
cubic  centimeters  of  distilled  water. 

Potassium  Iodide.  —  Dissolve  20  grams  of  potassium  iodide 
in  100  cubic  centimeters  of  distilled  water. 

Standard  Potassium  Cyanide.  —  Dissolve  2.29  grams  of  potas- 
sium cyanide  in  1,000  cubic  centimeters  of  distilled  water. 
Standardize  this  solution  by  the  procedure  described  below, 
against  a  steel  of  known  nickel  content  as  determined  by  the 
gravimetric  dimethylglyoxime  method,  so  that  each  cubic  centi- 
meter is  equivalent  to  0.05  per  cent,  of  nickel  on  the  basis  of 
a  i  -gram  sample  (see  notes). 

Method. 

In  a  150  cubic  centimeter  beaker  dissolve  I  gram  of  the 
steel  in  20  cubic  centimeters  of  the  hydrochloric  acid,  and  add 
about  2  cubic  centimeters  of  nitric  acid,  specific  gravity  1.42, 
to  oxidize  the  iron.  Filter  the  solution  and  add  to  the  fil- 
trate 6  grams  of  tartaric  acid,  and  water  until  the  volume  is 
300  cubic  centimeters.  Make  the  solution  faintly  ammoniacal, 
then  faintly  acid  with  the  hydrochloric  acid,  and  cool  thor- 
oughly. Add  20  cubic  centimeters  of  the  dimethylglyoxime 
solution  and  then  ammonium  hydroxide,  specific  gravity  0.90, 
drop  by  drop,  till  faintly  alkaline,  stirring  vigorously.  After 
standing  for  a  few  minutes,  filter  on  a  Gooch  crucible  arid 
wash  with  hot  water.  Dissolve  the  precipitate  on  the  filter 
with  10  to  20  cubic  centimeters  of  nitric  acid  (hot),  specific 


297 

gravity  1.42,  added  drop  by  drop,  and  then  wash  5  times  with 
hot  water,  using  suction.  To  the  solution  in  a  500  cubic  centi- 
meter beaker  add  3  grams  of  ammonium  persulphate  and  boil 
for  5  minutes.  Cool,  make  distinctly  ammoniacal,  add  10 
cubic  centimeters  each  of  the  silver  nitrate  and  potassium 
iodide  solutions,  and  titrate  with  the  standard  potassium  cy- 
anide solution  to  a  faint  turbidity. 

NOTES. 

In  making  dimethylglyoxime  solution,  methyl  alcohol  may  be  sub- 
stituted for  ethyl  alcohol. 

Bureau  of  Standards  Standard  Steel  No.  33  is  recommended  for 
standardizing  the  potassium  cyanide  solution. 

The  weight  of  sample  taken  should  be  varied  according  to  the 
nickel  content. 

DETERMINATION  OF  CHROMIUM. 

Solutions  Required. 

Hydrochloric  Acid. — Mix  500  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  and  500  cubic  centimeters 
of  distilled  water. 

Sodium  Carbonate. — A  saturated  solution;  approximately 
60  grams  of  sodium  carbonate  and  100  cubic  centimeters  of 
distilled  water. 

Barium  Carbonate. — Ten  grams  of  finely  divided "  barium 
carbonate  suspended  in  100  cubic  centimeters  of  distilled 
water. 

Standard  Sodium  Chromate. — Dissolve  2.6322  grams  of 
sodium  chromate  in  1,000  cubic  centimeters  of  distilled  water. 
Each  cubic  centimeter  is  equivalent  to  0.02  per  cent,  chro- 
mium, when  a  5-gram  sample  is  used. 

Standard  Potassium  Permanganate. — Dissolve  2  grams  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  dis- 
tilled water.  Standardize  by  using  Bureau  of  Standards  so- 
dium oxalate,1  and  dilute  the  solution  with  distilled  water  so 
that  i  cubic  centimeter  is  equivalent  to  0.02  per  cent,  chro- 
mium, when  a  5-gram  sample  is  taken. 

1  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


298 

The  factor  Na2C2O4  »-*  Cr  =  0.2584  (using  the  1913  atomic 
weights). 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammoni- 
um sulphate  in  900  cubic  centimeters  of  distilled  water  and 
100  cubic  centimeters  of  sulphuric  acid  ( I :  I ) . 

Method. 

In  a  300  cubic  centimeter  Erlenmeyer  flask,  covered,  dis- 
solve 5  grams  of  steel  in  50  cubic  centimeters  of  the  hydro- 
chloric acid.  When  completely  dissolved,  and  gradually  the 
saturated  solution  of  sodium  carbonate  until  practically  all  the 
free  acid  is  neutralized;  finish  the  neutralization  with  the  ba- 
rium carbonate  suspension,  using  an  excess  of  about  I  gram 
of  the  carbonate.  Boil  the  solution  in  the  flask  for  10  or  15 
minutes,  with  the  cover  on.  Filter  the  precipitate  rapidly  on 
paper  and  wash  twice  with  hot  water.  Transfer  the  filter  to 
a  platinum  crucible  and  after  burning  off  the  paper,  fuse  the 
residue  for  10  minutes  with  a  mixture  of  5  grams  of  sodium 
carbonate  and  0.25  gram  of  potassium  nitrate.  Dissolve  the 
fusion  in  water,  transfer  to  a  beaker,  add  2  cubic  centimeters 
of  3  per  cent,  hydrogen  peroxide,  boil  a  few  minutes  and 
filter.  Complete  the  determination  of  chromium  in  the  filtrate 
by  either  of  the  following  procedures: 

1.  If  the  solution  is  a  strong  yellow,  add   10  cubic  centi- 
meters of  sulphuric  acid  (i :  i),  and  then  the  ferrous  sulphate 
solution   in   measured   excess.      Cool   thoroughly   and   titrate 
with   the   standard   potassium   permanganate   solution.      The 
number  of  cubic  centimeters  of  the  potassium  permanganate 
solution  obtained,  subtracted  from  the  number  corresponding 
to  the  volume  of  the  ferrous  sulphate  solution  used,  will  give 
the  volume  of  the  potassium  permanganate  solution  equivalent 
to  the  chromium  in  the  sample. 

2.  If  the  solution  is  a  light  yellow,  cool  the  'solution  and 
transfer  to  a  100  cubic  centimeter  Nessler  tube.     To  another 
Nessler  tube  add  distilled  water,  and  from  a  burette  add  the 
standard   sodium   chromate   solution  until   the  yellow   colors 
match. 


299 

NOTE. 

If  procedure  No.  I  is  used,  all  hydrogen  peroxide  must  be 
destroyed  by  boiling  before  acidifying,  otherwise  chromic  acid  will  be 
reduced  at  this  stage. 

CHEMICAL  ANALYSIS  OF  ALLOY  STEELS  AS  PUBLISHED  BY  THE 

AMERICAN  SOCIETY  FOR  TESTING  MATERIALS. 

ADOPTED,  1915. 

NICKEL  STEEL. 

Determination  of  Carbon. 

See  the  Determination  of  Carbon  in  Plain  Carbon  Steel  by 
the  Direct-Combustion  Method.1 

Determination  of  Manganese. 

See  the  Determination  of  Manganese  in  Plain  Carbon  Steel 
by  the  Bismuthate  Method.1 

See  the  Determination  of  Manganese  in  Plain  Carbon  Steel 
by  the  Persulphate  Method  (Routine). 

Determination  of  Phosphorus. 

See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Molybdate  Magnesia  Method.1 

See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Alkalimetric  Method  (Routine).1 

Determination  of  Sulphur. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Oxidation  Method.1 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Evolution-Titration  Method  (Routine).1 

NOTES. 

The  Evolution-Titration  Method  should  not  be  used  with  steels 
containing  appreciable  amounts  of  tungsten,  or  of  copper  or  other 
metals  precipitated  by  hydrogen  sulphide  from  acid  solutions. 

The  annealing  of  the  steel  drillings  has  been  found  by  a  number 
of  investigators  to  increase  the  degree  of  refinement  of  the  method. 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


300 

Determination  of  Silicon. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Nitro-Sulphuric  Method.1 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Sulphuric  Acid  Method  (Optional).1 

Determination  of  Nickel. 

See  the  Determination  of  Nickel  in  Plain  Carbon  Steel  by 
the  Gravimetric  Dimethylglyoxime  Method.1 

See  the  Determination  of  Nickel  in  Plain  Carbon  Steel  by 
the  Volumetric  Dimethylglyoxime  Method  (Routine).1 

Determination  of  Nickel  by  the  Ether  Extraction-Cyanide 
Titratio  n  Meth  o  d . 

(Optional  Routine.) 
SOLUTIONS  REQUIRED. 

Hydrochloric  Acid. — Mix  600  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  and  400  cubic  centimeters  of 
distilled  water. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1.200  cubic  centimeters  of  distilled 
water. 

Potassium  Iodide. — Dissolve  20  grams  of  potassium  iodide 
in  1,000  cubic  centimeters  of  distilled  water. 

Silver  Nitrate. — Dissolve  0.5  gram  of  silver  nitrate  in  1,000 
cubic  centimeters  of  distilled  water. 

Standard  Potassium  Cyanide. — Dissolve  4.589  grams  of 
potassium  cyanide  in  1,000  cubic  centimeters  of  distilled  water. 
Standardize  the  solution  by  the  procedure  described  below, 
against  a  steel  of  known  nickel  content  as  determined  by  the 
gravimetric-dimethylglyoxime  method,  so  that  I  cubic  centi- 
meter is  equivalent  to  o.io  per  cent,  nickel  on  the  basis  of  a 
i -gram  sample  (see  note). 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


3oi 

METHOD. 

In  a  150  cubic  centimeter  beaker  dissolve  i  gram  of  the  steel 
in  20  cubic  centimeters  of  the  hydrochloric  acid,  add  about 
2  cubic  centimeters  of  nitric  acid,  specific  gravity  1.42,  to 
oxidize  the  iron,  and  boil  to  expel  the  oxides  of  nitrogen. 
Cool,  and  transfer  the  solution  into  an  8-ounce  separatory 
funnel,  rinsing  the  beaker  with  small  portions  of  the  hydro- 
chloric acid.  Add  50  cubic  centimeters  of  ether,  shake  for  5 
minutes,  let  settle  for  I  minute,  and  then  draw  off  lower  clear 
solution  into  another  8-ounce  separatory  funnel.  Add  10 
cubic  centimeters  of  hydrochloric  acid,  specific  gravity  1.20,  to 
the  solution  in  the  first  separatory  funnel,  cool,  shake  thor- 
oughly, allow  to  settle  for  I  minute,  and  then  draw  off  the 
lower  clear  solution  into  the  second  separatory  funnel.  To 
the  combined  solutions  in  the  second  separatory  funnel  add 
50  cubic  centimeters  of  ether,  shake  for  5  minutes,  let  settle  for 
i  minute,  and  then  draw  off  the  clear  layer  into  a  150  cubic 
centimeter  beaker.  Heat  the  aqueous  solution  gently  to  expel 
the  ether,  add  0.2  gram  of  potassium  chlorate,  boil  until 
chlorate  is  decomposed,  dilute  to  100  cubic  centimeters  with 
hot  water,  make  faintly  ammoniacal,  and  boil  for  5  minutes. 
Filter  and  wash  with  hot  water.  To  the  filtrate  add  10  cubic 
centimeters  of  hydrochloric  acid,  specific  gravity  1.20,  heat  just 
short  of  boiling  and  precipitate  the  copper  with  hydrogen  sul- 
phide. Filter  and  wash  with  hot  water.  Boil  the  filtrate  to 
expel  hydrogen  sulphide,  reducing  the  volume  by  evaporation 
to  approximately  100  cubic  centimeters,  cool,  and  make  solu- 
tion distinctly  ammoniacal,  add  10  cubic  centimeters  each  of 
the  silver-nitrate  and  potassium-iodide  solutions,  and  titrate 
with  the  standard  potassium-cyanide  solution  to  a  clear  solu- 
tion. 

NOTE. 

Bureau  of  Standards  Standard  Steel  No.  33  is  recommended  for 
standardizing  the  potassium  cyanide  solution. 


20 


302 


Determination  of  Carbon. 

See  the  Determination  of  Carbon  by  the  Direct-Combustion 
Method.1 

Determination  of  Manganese  by  the  Zinc  Oxlde- 
Bismuthate  Method. 

SOLUTIONS  REQUIRED. 

Sulphuric  Acid.  —  Mix  200  cubic  centimeters  of  sulphuric 
acid,  specific  gravity  1.84,  and  800  cubic  centimeters  of  dis- 
tilled water. 

Nitric  Acid.  —  Mix  500  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42  and  1,500  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing.  —  Mix  30  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  970  cubic  centimeters  of 
distilled  water. 

Sodium  Carbonate.  —  A  saturated  solution;  approximately 
60  grams  of  sodium  carbonate  and  100  cubic  centimeters  of 
distilled  water. 

Zinc  Oxide.  —  Twenty  grams  of  zinc  oxide  (dry  process) 
suspended  in  100  cubic  centimeters  of  distilled  water  (see 
notes). 

Stock  Sodium  Arsenite.  —  To  15  grams  of  arsenious  oxide 
(As2O3)  in  a  300  cubic  centimeter  Erlenmeyer  flask,  add  45 
grams  of  sodium  carbonate  and  150  cubic  centimeters  of  dis- 
tilled water.  Heat  the  flask  and  contents  on  a  water  bath  until 
the  arsenious  oxide  is  dissolved,  cool  the  solution  and  make  up 
to  1,000  cubic  centimeters  with  distilled  water. 

Standard  Sodium-  Arsenite.  —  Dilute  300  cubic  centimeters  of 
the  stock-sodium-arsenite  solution  to  1,000  cubic  centimeters 
with  distilled  water  and  titrate  against  potassium-permangan- 
ate solution  (about  N/io)  which  has  been  standardized  by 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


303 

using  Bureau  of  Standards  sodium  oxalate.1  Adjust  the  solu- 
tion so  that  I  cubic  centimeter  is  equivalent  to  o.io  per  cent,  of 
manganese  on  the  basis  of  a  i-gram  sample. 

The   factor   Na2C2O4 — >  Mn  ==  0.16397    (using   the  1913 
atomic  weights). 

METHOD. 

In  a  platinum  or  porcelain  dish  of  300  cubic  centimeters 
capacity,  to  2.5  grams  of  the  steel  add  40  cubic  centimeters  of 
the  sulphuric  acid,  cover  with  a  watch  glass,  and  heat  until 
the  steel  is  dissolved.  Add  about  4  cubic  centimeters  of  nitric 
acid,  specific  gravity  1.42,  to  oxidize  the  iron  and  evaporate 
slowly  until  copious  fumes  of  sulphuric  acid  are  evolved. 
Cool,  add  100  cubic  centimeters  of  hot  water,  heat  with  fre- 
quent stirring  until  all  salts  are  dissolved,  then  transfer  the 
solution  into  a  volumetric  500  cubic  centimeter  flask.  Add  the 
sodium-carbonate  solution  until  near  neutrality,  and  the  pre- 
cipitate formed  dissolves  with  difficulty,  then  add  small  por- 
tions of  the  zinc-oxide  suspension,  shaking  vigorously  after 
each  addition,  until  after  settling  of  the  coagulated  precipitate, 
the  supernatant  liquid  is  practically  clear.  Cool,  and  make 
up  to  the  mark  with  water.  Mix  thoroughly  by  pouring  the 
entire  contents  of  the  flask  into  a  large,  dry  beaker,  and  back 
again  to  the  flask,  repeating  several  times.  Allow  the  pre- 
cipitate to  settle,  filter  off  200  cubic  centimeters  of  the  solution 
into  a  300  cubic  centimeter  Erlenmeyer  flask,  add  25  cubic 
centimeters  of  the  nitric  acid  solution,  and  boil  to  expel  the 
oxides  of  nitrogen.  Cool,  add  0.5  gram  of  sodium  bismuthate 
and  heat  for  a  few  minutes,  or  until  the  pink  color  has  disap- 
peared, with  or  without  the  precipitation  of  manganese  dioxide. 
Add  small  portions  of  ferrous  sulphate  (or  other  suitable  re- 
ducing agent)  in  sufficient  quantity  to  clear  the  solution,  and 
boil  to  expel  the  oxides  of  nitrogen.  Cool  to  15°  C.,  add  an 
excess  of  sodium  bismuthate  and  agitate  for  a  few  minutes. 
Let  settle  and  filter  through  an  alundum  filter  or  asbestos  pad, 
washing  with  the  3  per  cent,  nitric  acid.  Titrate  immediately 

1  Circular  No .  40 ,  Bureau  of  Standards,  Oct.  i,  1912. 


304 

* 

with  the  standard  sodium-arsenite  solution  to  the  disappear- 
ance of  the  pink  color. 

NOTES. 

In  the  method,  the  preliminary  treatment  with  sodium  bismuthate 
has  been  found  by  a  number  of  investigators  to  be  apparently  unneces- 
sary ;  however,  the  available  data  to  confirm  this  position  are  not  con- 
sidered sufficient  to  warrant  its  omission. 

In  making  the  asbestos  filter  pad  it  is  advisable  to  have  a  thin  bed 
and  as  much  surface  as  possible.  This  insures  rapid  filtration  and  the 
filter  may  be  used  until  it  becomes  clogged  with  bismuthate. 

The  filtrate  must  be  perfectly  clear  since  the  least  particle  of 
bismuthate  carried  through  the  filter  will  vitiate  the  results. 

The  zinc-oxide  reagent  should  be  free  from  manganese,  or  a  cor- 
rection applied  if  it  is  present. 

Determination  of  Manganese  by  the  Modified 
Bismuthate  Method. 

(Routine.) 
SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  500  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,500  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  30  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  970  cubic  centimeters  of 
distilled  water. 

Stock  Sodium  Arsenite.—To  15  grams  of  arsenious  oxide 
(As2O3)  in  a  300  cubic  centimeter  Erlenmeyer  flask,  add  45 
grams  of  sodium  carbonate  and  150  cubic  centimeters  of  dis- 
tilled water.  Heat  the  flask  and  contents  on  a  water  bath  until 
the  arsenious  oxide  is  dissolved,  cool  the  solution  and  make  up 
to  1,000  cubic  centimeters  with  distilled  water. 

Standard  Sodium  Arsenite. — Dilute  300  cubic  centimeters  of 
the  stock-sodium-arsenite  solution  to  1,000  cubic  centimeters 
with  distilled  water  and  titrate  against  potassium-permangan- 
ate solution  (about  N/io)  which  has  been  standardized  by 
using  Bureau  of  Standards  sodium  oxalate.1  Adjust  the  solu- 

i  Circular  No.  40,  Bureau  of  Standards,  Oct.  i  1912. 


305 

tion  so  that  i  cubic  centimeter  is  equivalent  to  o.io  per  cent,  of 
manganese  on  the  basis  of  a  i-gram  sample. 

The  factor  Na2C2O4  -  >  Mn  ==  0.16397  (using  the  1913 
atomic  weights). 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  I  gram 
of  the  steel  in  50  cubic  centimeters  of  the  nitric  acid,  and  boil 
to  expel  the  oxides  of  nitrogen.  Cool  to  60-70°  C.,  add  about 
0.5  gram  of  sodium  bismuthate,  and  heat  for  a  few  minutes, 
or  until  the  pink  color  has  disappeared,  with  or  without  the 
precipitation  of  manganese  dioxide.  Add  sufficient  sulphurous 
acid  or  sodium  sulphite  to  clear  the  solution  and  to  reduce 
all  of  the  chromic  acid.  Cool  to  approximately  o°  C.  in  ice 
water,  add  an  excess  of  sodium  bismuthate  and  agitate.  After 
30  seconds  standing,  filter  rapidly  through  an  alundum  filter 
or  asbestos  pad,  washing  with  3  per  cent,  nitric  acid  previously 
cooled  in  ice  water  to  approximately  o°  C.  Titrate  immedi- 
ately with  the  standard  sodium-arsenite  solution  to  the  disap- 
pearance of  the  pink  color. 

NOTES. 

In  the  method,  the  preliminary  treatment  with  sodium  bismuthate 
has  been  found  by  a  number  of  investigators  to  be  apparently  unneces- 
sary; however,  the  available  data  to  confirm  this  position  are  not 
sufficient  to  warrant  its  omission. 

In  making  the  asbestos  filter  pad  it  is  advisable  to  have  a  thin 
bed,  and  as  much  surface  as  possible.  This  insures  rapid  filtration, 
and  the  filter  may  be  used  until  it  becomes  clogged  with  bismuthate. 

The  filtrate  must  be  ice  cold  and  perfectly  clear,  since  any  appre- 
ciable rise  of  temperature  above  o°  C.,  or  the  least  particle  of  bis- 
muthate carried  through  the  filter  will  vitiate  the  results. 

See  the  Determination  of  Manganese  in  Plain  Carbon  Steel 
by  the  Persulphate  Method.1 

NOTE. 

In  making  the  titration  special  care  should  be  given  to  standard- 
izing the  end-point  reading,  and  the  reading  should  be  corrected  by  a 
blank,  which  varies  with  the  amount  of  chromium  present. 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


3°6 

Determination  of  Phosphorus. 

See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Molybdate-Magnesia  Method.1 

See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Alkalimetric  Method.1 

Determination  of  Sulphur. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Oxidation  Method.1 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Evolution-Titration  Method  (Routine).1 

NOTES. 

The  Evolution-Titration  Method  should  not  be  used  with  steels 
containing  appreciable  amounts  of  tungsten,  or  of  copper  or  other 
metals  precipitated  by  hydrogen  sulphide  from  acid  solutions. 

The  annealing  of  the  steel  drillings  has  been  found  by  a  number 
of  investigators  to  increase  the  degree  of  refinement  of  the  method. 

Determination  of  Silicon. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Nitro-Sulphuric  Method.1 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Sulphuric  Acid  Method  (Optional).1 

Determination  of  Chromium  by  the  Fusion  Method. 

SOLUTIONS  REQUIRED. 

Sulphuric  Acid. — Mix  1,000  cubic  centimeters  of  sulphuric 
acid,  specific  gravity  1.84,  and  3,000  cubic  centimeters  of  dis- 
tilled water. 

Sodium  Carbonate. — A  saturated  solution;  approximately 
60  grams  of  sodium  carbonate  and  100  cubic  centimeters  of 
distilled  water. 

Magnesium  Carbonate. — Ten  grams  of  finely  divided  mag- 
nesium carbonate  suspended  in  100  cubic  centimeters  of  dis- 
tilled water. 

Barium  Carbonate. — Ten  grams  of  finely  divided  barium 
carbonate  suspended  in  100  cubic  centimeters  of  distilled  water. 


307 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Potassium-Ferricyanide  Indicator. — Dissolve  o.i  gram  of 
potassium  ferricyanide  in  50  cubic  centimeters  of  distilled 
water  (see  notes). 

Standard  Potassium  Bichromate. — Dissolve  5  grams  of  po- 
tassium bichromate  in  1,000  cubic  centimeters  of  distilled 
water,  standardize  against  pure  ferrous  ammonium  sulphate, 
and  adjust  to  tenth-normal. 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammonium 
sulphate  in  900  cubic  centimeters  of  distilled  water  and  100 
cubic  centimeters  of  sulphuric  acid  (i :  i). 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask,  covered,  dissolve 
i  gram  of  the  steel  in  50  cubic  centimeters  of  the  sulphuric  acid 
(see  notes).  When  completely  dissolved,  add  50  to  75  cubic 
centimeters  of  hot  water,  then  gradually  the  sodium-carbonate 
solution  until  near  neutrality,  then  add  an  excess  of  the  mag- 
nesium-carbonate suspension  (see  notes),  and  boil  vigorously 
for  15  minutes,  with  the  cover  on,  adding  fresh  portions  of  the 
carbonate  suspension  during  this  time,  so  that  there  is  present 
in  the  solution  at  the  end  of  the  operation  an  excess  of  2  to 
3  grams  of  the  carbonate.  Let  settle  and  pour  the  supernatant 
liquid  on  a  rapid  filter,  washing  by  decantation  twice  with  cold 
water,  pouring  the  washings  through  the  filter.  Transfer  the 
filter  to  a  platinum  crucible  and  after  burning  off  the  paper, 
fuse  the  residue  for  10  minutes  with  a  mixture  of  5  grams  of 
sodium  carbonate  and  0.25  gram  of  potassium  nitrate.  Dis- 
solve the  fusion  in  water,  transfer  to  a  beaker,  add  2  cubic 
centimeters  of  3  per  cent,  hydrogen  peroxide,  boil  a  few 
minutes  and  filter.  Add  20  cubic  centimeters  of  the  sulphuric 
acid,  stir  vigorously,  cool  and  titrate  against  the  standardized 
ferrous-sulphate  solution,  using  the  potassium-ferricyanide 
solution  as  outside  indicator,  or  add  at  once  a  measured  amount 
(in  excess)  of  the  ferrous-sulphate  solution,  and  titrate  back 


3o8 

against  the  potassium-bichromate  solution,  using  the  same  in- 
dicator. 

NOTES. 

The  solution  of  the  steel  may  be  in  hydrochloric  acid,  specific 
gravity  1.20  or  any  other  desired  strength,  adjusting  the  amount  of 
acid  used  to  avoid  a  large  excess  being  present. 

Barium  carbonate  suspension  may  be  substituted  for  the  mag- 
nesium carbonate  suspension  when  hydrochloric  acid  is  used  as  solvent. 

All  hydrogen  peroxide  must  be  destroyed  by  boiling  before  acidi- 
fying, otherwise  chromic  acid  will  be  reduced  at  this  stage. 

The  insoluble  residue  remaining  after  extraction  of  the  fusion 
should  be  examined  for  chromium. 

The  potassium  ferricyanide  indicator  should  be  prepared  fresh  on 
the  day  it  is  used. 

The  ferrous  sulphate  solution  should  be  standardized  on  the  day 
it  is  used. 

In  titrating  with  the  ferrous  sulphate  solution  it  is  convenient  to 
divide  the  solution,  roughly  titrate  one  portion,  add  the  other  and  finish 
carefully. 

Determination  of  Chromium  by  the  Chlorate  Method. 
(Routine.)  ' 

SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Potassium-Ferricyanide  Indicator. — Dissolve  o.i  gram  of 
potassium  ferricyanide  in  50  cubic  centimeters  of  distilled 
water  (see  notes). 

Standard  Potassium  Bichromate.— Dissolve  5  grams  of  po- 
tassium bichromate  in  1,000  cubic  centimeters  of  distilled 
water,  and  standardize  against  pure  ferrous  ammonium  sul- 
phate, and  adjust  to  tenth-normal. 

Standard  Potassium  Permanganate. — Dissolve  2  grams  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  distilled 
water.  Standardize  by  using  Bureau  of  Standards  sodium 
oxalate.1  Adjust  the  solution  so  that  I  cubic  centimeter  is 
equivalent  to  o.io  per  cent,  chromium  on  the  basis  of  a  i-gram 

1  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


309 

sample.     The  factor  Na2C2O4  >  Cr  —  0.2584  (using  the  1913 
atomic  weights). 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammonium 
sulphate  in  900  cubic  centimeters  of  distilled  water  and  100 
cubic  centimeters  of  sulphuric  acid  (i  :  i). 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  I  gram 
of  the  steel  in  30  cubic  centimeters  of  the  nitric  acid,  and 
evaporate  rapidly  to  approximately  one-half  volume.  Add  50 
cubic  centimeters  of  nitric  acid,  specific  gravity  1.42,  and  add 
i  gram  of  sodium  chlorate  (see  notes).  Evaporate  to  boiling 
to  approximately  one-half  volume  and  complete  the  determina- 
tion by  either  of  the  following  procedures : 

1.  Dilute  the  solution  with  100  cubic  centimeters  of  distilled 
water  and  filter  off  the  manganese  dioxide,  using  suction,  wash- 
ing with  hot  water.    Cool  the  filtrate,  dilute  with  cold  water  to 
600  cubic  centimeter  volume,  and  titrate  against  the  standard 
ferrous-sulphate    solution,    using    the    potassium-ferricyanide 
solution   as   outside   indicator,    or   add   at   once    a   measured 
amount  (in  excess)  of  the  ferrous-sulphate  solution  and  titrate 
back  against  the  standard  potassium-bichromate  solution,  using 
the  same  indicator. 

2.  Add  10  cubic  centimeters  of  hydrochloric  acid  (i :  i)  and 
boil  until  the  solution  is  clear  and  all  manganese  dioxide  dis- 
solved.    Cool,  dilute  the  solution  with  water  to  300  cubic  centi- 
meter volume,  add  the  ferrous-sulphate  solution  in  measured 
amount   (in  excess),  and  titrate  back  with  the  standard  po- 
tassium-permanganate solution  to  a  permanent  pink  color. 

NOTES. 

The  potassium-ferricyanide  indicator  should  be  prepared  fresh  on 
the  day  it  is  used. 

The  ferrous-sulphate  solution  should  be  compared  on  the  day  it  is 
used,  with  the  standard  potassium-permanganete  or  standard  potas- 
sium-bichromate solutions. 

Potassium  chlorate  may  be  used  as  oxidizing  agent  in  the  place 
of  sodium  chlorate. 

In  titrating  with  the  ferrous-sulphate  solution  it  is  convenient  to 
divide  the  solution,  roughly  titrate  one  portion,  add  the  other  and 
finish  carefully. 


3io 

.  Determination  of  Chromium  by  the  Permanganate 
Oxidation  Method. 

(Optional  Routine.) 
SOLUTIONS  REQUIRED. 

Sulphuric  Add. — Mix  1,000  cubic  centimeters  of  sulphuric 
acid,  specific  gravity  1.84,  and  3,000  cubic  centimeters  of  dis- 
tilled water. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Standard  Potassium  Permanganate. — Dissolve  2  grams  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  distilled 
water.  Standardize  by  using  Bureau  of  Standard  sodium 
oxalate.1  Adjust  the  solution  so  that  i  cubic  centimeter  is 
equivalent  to  o.io  per  cent,  chromium  on  the  basis  of  a  i-gram 
sample. 

The  factor  Na2C2O4 — >  Cr=  0.2584  (using  the  1913  atomic 
weights). 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammonium 
sulphate  in  900  cubic  centimeters  of  distilled  water  and  100 
cubic  centimeters  of  sulphuric  acid  (i :  i). 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask,  dissolve  1.25 
grams  (procedure  No.  i)  or  i  gram  (procedure  No.  2)  of  the 
steel  in  50  cubic  centimeters  of  the  sulphuric  acid.  When  com- 
pletely dissolved,  add  5  cubic  centimeters  of  the  nitric  acid,  and 
boil  until  clear  and  free  from  oxides  of  nitrogen.  Dilute  with 
hot  water  to  approximately  150  cubic  centimeter  volume,  heat, 
and  while  boiling  add  the  potassium-permanganate  solution 
slowly  until  a  permanent  brown  precipitate  appears  (see 
notes).  Complete  the  determination  by  either  of  the  following 
procedures : 

1  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


1.  Add  25  cubic  centimeters  of  ammonium  hydroxide,  spe- 
cific gravity  0.90,  shake  well,  place  on  the  cooler  part  of  the  hot 
plate  to  avoid  bumping.     Shake  occasionally  and  digest  for 
about  15  minutes,  or  until  the  permanganate  is  all  decomposed, 
then  add  cautiously  20  cubic  centimeters  of  the  sulphuric  acid 
and  bring  gently  to  a  boil.     Cool  the  solution  and  pour  into  a 
volumetric  250  cubic  centimeter  flask.    Make  up  to  mark  with 
cold  water  and  mix  thoroughly.     Allow  precipitate  to  settle, 
filter  off  200  cubic  centimeters  of  the  clear  solution  (equal  to 
i  gram),  add  the  ferrous-sulphate  solution  in  measured  amount 
(in  excess)  and  titrate  back  with  the  standard  potassium-per- 
manganate solution  to  a  permanent  pink  color.     The  number 
of  cubic  centimeters  of  the  standard  potassium-permanganate 
solution  obtained,  subtracted  from  the  number  corresponding 
to  the  volume  of  the  ferrous-sulphate  solution  used,  will  give 
the  volume  of  the  standard  potassium-permanganate  solution 
equivalent  to  the  chromium  in  the  sample. 

2.  Add  10  cubic  centimeters  of  hydrochloric  acid  (i :  i),  and 
boil  until  the  solution  is  clear  and  all  manganese  dioxide  dis- 
solved.   Cool,  dilute  the  solution  with  water  to  300  cubic  centi- 
meter volume,  add  the  ferrous-sulphate  solution  in  measured 
amount   (in  excess),  and  titrate  back  with  the  standard  po- 
tassium-permanganate solution  to  a  permanent  pink  color. 

NOTES. 

In  oxidizing  with  the  potassittm-permanganate  solution  care  should 
be  taken  to  avoid  a  large  excess,  since  the  manganese-dioxide  precipi- 
tate tends  to  hold  the  chromic  acid. 

In  the  solution  of  the  manganese  dioxide  under  procedure  No.  2, 
the  boiling  should  be  continued  until  all  chlorine  fumes  are  expelled. 

The  ferrous-sulphate  solution  should  be  compared  on  the  day  it  is 
used  with  the  standard  potassium-permanganate  solution. 

Determination  of  Nickel. 

See  the  Determination  of  Nickel  in  Plain  Carbon  Steel  by 
the  Gravimetric-Dimethylglyoxime  Method.1 

i  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915,  Year-Book,  p.  201. 


312 

See  the  Determination  of  Nickel  in  Plain  Carbon  Steel  by 
the  Volumetric  Dimethylglyoxime  Method  (Routine). 

VANADIUM  STEEL. 
Determination  of  Carbon. 

See  the  Determination  of  Carbon  in  Plain  Carbon  Steel  by 
the  Direct-Combustion  Method. 

Determination  of  Manganese. 

See  the  Determination  of  Manganese  in  Chrome-Nickel 
Steel  by  the  Zinc  Oxide-Bismuthate  Method. 

For  the  Routine  Determination  of  Manganese,  see  the  De- 
termination of  Manganese  in  Plain  Carbon  Steel  by  the  Bis- 
muthate  Method. 

Determination  of  Phosphorus  by  the  Modified 

Molybdate-Magnesia  Method. 

SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  20  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters 
of  distilled  water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Sodium  Bisulphite. — Dissolve  30  grams  of  sodium  bisulphite 
in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Molybdate. — Solution  No.  I, — Place  in  a  beaker 
100  grams  of  85  per  cent,  molybdic  acid,  mix  it  thoroughly 
with  240  cubic  centimeters  of  distilled  water,  add  140  cubic 
centimeters  of  ammonium  hydroxide,  specific  gravity  0.90,  fil- 
ter, and  add  60  cubic  centimeters  of  nitric  acid,  specific  gravity 
1.42. 


Solution  No.  2. — Mix  400  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  960  cubic  centimeters  of  distilled 
water. 

When  the  solutions  are  cold,  add  solution  No.  I  to  solution 
No.  2,  stirring  constantly;  then  add  o.i  gram  of  ammonium 
phosphate  dissolved  in  10  cubic  centimeters  of  distilled  water, 
and  let  stand  at  least  24  hours  before  using. 

Magnesia  Mixture. — Dissolve  50  grams  of  magnesium  chlo- 
ride and  125  grams  of  ammonium  chloride  in  750  cubic  centi- 
meters of  distilled  water  and  then  add  150  cubic  centimeters 
of  ammonium  hydroxide,  specific  gravity  0.90. 

Ammonium  Hydroxide,  Approximately  10  per  cent. — Mix 
1,000  cubic  centimeters  of  ammonium  hydroxide,  specific 
gravity  0.90,  and  2,000  cubic  centimeters  of  distilled  water. 

Ferrous  Sulphate. — A  saturated  solution;  approximately  40 
grams  of  ferrous  sulphate  and  100  cubic  centimeters  of  dis- 
tilled water. 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  5  grams 
of  steel  in  75  cubic  centimeters  of  the  nitric  acid.  Heat,  and 
while  boiling  add  about  12  cubic  centimeters  of  the  potassium- 
permanganate  solution,  and  continue  boiling  until  manganese 
dioxide  precipitates.  Dissolve  the  precipitate  by  additions  of 
the  sodium-bisulphite  solution,  boil  until  clear  and  free  from 
oxides  of  nitrogen.  Cool  to  15-20°  C.,  add  5  cubic  centimeters 
of  the  ferrous-sulphate  solution,  and  2  or  3  drops  of  con- 
centrated sulphurous  acid,  and  then  100  cubic  centimeters  of 
the  ammonium-molybdate  solution.  Let  stand  I  minute,  shake 
or  agitate  thoroughly  for  5  minutes,  filter  on  a  9-centimeter 
paper  and  wash  at  least  3  times  with  the  2  per  cent,  nitric  acid 
solution  to  free  from  iron. 

Treat  the  precipitate  on  the  filter  with  the  10  per  cent,  am- 
monium-hydroxide solution,  letting  the  solution  run  into  a 
100  cubic  centimeter  beaker  containing  10  cubic  centimeters  of 
hydrochloric  acid,  specific  gravity  1.20,  and  0.5  gram  of  citric 
acid;  add  30  cubic  centimeters  of  ammonium  hydroxide, 


3*4 

specific  gravity  0.90,  cool,  and  then  add  10  cubic  centimeters  of 
the  magnesia  mixture  very  slowly,  while  stirring  the  solution 
vigorously.  Set  aside  in  a  cool  place  for  2  hours,  filter  and 
wash  with  the  10  per  cent,  ammonium-hydroxide  solution.  Ig- 
nite and  weigh.  Dissolve  the  precipitate  of  magnesium  pyro- 
phosphate  with  5  cubic  centimeters  of  nitric  acid,  specific 
gravity  1.20,  and  20  cubic  centimeters  of  water,  filter  and 
wash  with  hot  water.  Ignite  and  weigh.  The  difference  in 
weights  represents  pure  magnesium  pyrophosphate  containing 
27.84  per  cent,  of  phosphorus. 

NOTE. 

The  ammonium-molybdate  solution  should  be  kept  in  a  cool  place 
and  should  always  be  filtered  before  using. 

Determination  of  Phosphorus  by  the  Modified 
Alkalimetric  Method. 

(Routine.) 
SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  20  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters  of 
distilled  water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Sodium  Bisulphite. — Dissolve  30  grams  of  sodium  bisulphite 
in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Molybdate. — Solution  No.  i. — Place  in  a  beaker 
100  grams  of  85  per  cent,  molybdic  acid,  mix  it  thoroughly 
with  240  cubic  centimeters  of  distilled  water,  add  140  cubic 
centimeters  of  ammonium  hydroxide,  specific  gravity  0.90,  fil- 
ter, and  add  60  cubic  centimeters  of  nitric  acid,  specific  gravity 
1.42. 

Solution  No.  2. — Mix  400  cubic  centimeters  of  nitric  acid, 


specific  gravity  1.42,  and  960  cubic  centimeters  of  distilled 
water. 

When  the  solutions  are  cold,  add  solution  No.  I  to  solu- 
tion No.  2,  stirring  constantly;  then  add  o.i  gram  of  ammoni- 
um phosphate  dissolved  in  10  cubic  centimeters  of  distilled 
water,  and  let  stand  at  least  24  hours  before  using. 

Ferrous  Sulphate. — A  saturated  solution;  approximately  40 
grams  of  ferrous  sulphate  and  100  cubic  centimeters  of  dis- 
tilled water. 

Potassium  Nitrate,  I  per  cent. — Dissolve  10  grams  of  potas- 
sium nitrate  in  1,000  cubic  centimeters  of  distilled  water. 

Phenolphthalein  Indicator. — Dissolve  0.2  gram  of  phenol- 
phthalein  in  50  cubic  centimeters  of  95  per  cent,  ethyl  alcohol 
and  50  cubic  centimeters  of  distilled  water. 

Standard  Sodium  Hydroxide. — Dissolve  6.5  grams  of  puri- 
fied sodium  hydroxide  in  1,000  cubic  centimeters  of  distilled 
wrater,  add  a  slight  excess  of  I  per  cent,  solution  of  barium 
hydroxide,  let  stand  for  24  hours,  decant  the  liquid,  and 
standardize  it  against  a  steel  of  known  phosphorus  content, 
as  determined  by  the  molybdate  magnesia  method,  so  that  I 
cubic  centimeter  will  be  equivalent  to  o.oi  per  cent,  of  phos- 
phorus on  the  basis  of  a  2-gram  sample  (see  notes).  Protect 
the  solution  from  carbon  dioxide  with  a  soda-lime  tube. 

Standard  Nitric  Acid. — Mix  10  cubic  centimeters  of  nitric 
acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters  of  dis- 
tilled water.  Titrate  the  solution  against  the  standardized 
sodium  hydroxide,  using  phenolphthalein  as  indicator,  and 
make  it  equivalent  to  the  sodium  hydroxide  by  adding  dis- 
tilled water. 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  2  grams 
of  steel  in  50  cubic  centimeters  of  the  nitric  acid.  Heat,  and 
while  boiling  add  6  cubic  centimeters  of  the  potassium  per- 
manganate solution  and  continue  boiling  until  manganese 
dioxide  precipitates.  Dissolve  this  precipitate  by  additions  of 
the  sodium  bisulphite  solution,  boil  until  clear  and  free  from 


3i6 

oxides  of  nitrogen,  cool  to  I5°-2O°  C.,  add  5  cubic  centimeters 
of  the  ferrous  sulphate  solution  and  2  or  3  drops  of  concen- 
trated sulphurous  acid,  and  then  50  cubic  centimeters  of  the 
ammonium  molybdate  solution.  Let  stand  for  i  minute,  shake 
or  agitate  for  5  minutes,  filter  on  a  9  centimeter  paper, 
wash  the  precipitate  three  times  with  the  2  per  cent,  nitric 
acid  solution  to  free  it  from  iron,  and  continue  the  washing 
with  the  i  per  cent,  potassium  nitrate  solution  until  the  pre- 
cipitate and  flask  are  free  from  acid. 

Transfer  the  paper  and  precipitate  to  the  solution  flask,  add 
20  cubic  centimeters  of  distilled  water  (see  notes),  5  drops  of 
phenolphthalein  solution  as  indicator,  and  an  excess  of  the 
standard  sodium  hydroxide  solution.  Insert  a  rubber  stopper 
and  shake  vigorously  until  solution  of  the  precipitate  is  com- 
plete. Wash  off  the  stopper  with  distilled  water  and  deter- 
mine the  excess  of  standard  sodium  hydroxide  solution  by 
titrating  with  standard  nitric  acid  solution.  Each  cubic  centi- 
meter of  standard  sodium  hydroxide  solution  represents  o.oi 
per  cent,  of  phosphorus. 

NOTES. 

The  ammonium-molybdate  solution  should  be  kept  in  a  cool  place 
and  should  always  be  filtered  before  using. 

All  distilled  water  used  in  titration  should  be  freed  from  carbon 
dioxide  by  boiling  or  otherwise. 

Bureau  of  Standards  Standard  Steel  No.  24  is  recommended  as  a 
suitable  steel  for  standardizing  the  sodium-hydroxide  solution. 

Determination  of  Sulphur. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel 
by  the  Oxidation  Method. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Evolution-Titration  Method  (Routine). 

NOTES. 

The  Evolution-Titration  Method  should  not  be  used  with  steels 
containing  appreciable  amounts  of  tungsten,  or  of  copper  or  other 
metals  precipitated  by  hydrogen  sulphide  from  acid  solutions. 

The  annealing  of  the  steel  drillings  has  been  found  by  a  number 
of  investigators  to  increase  the  degree  of  refinement  of  the  method. 


Determination  of  Silicon. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Nitro-Sulphuric  Method.1 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Sulphuric  Acid  Method  (Optional).1 

Determination  of  Vanadium  by   the  Phosphomolybdate-Pre- 
cipitation  Method. 

SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Nitric  Acid  for  Washing. — Mix  20  cubic  centimeters  of 
nitric  acid,  specific  gravity  1.42,  and  1,000  cubic  centimeters 
of  distilled  water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Sodium  Bisulphite. — Dissolve  30  grams  of  sodium  bisulphite 
in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Phosphate. — Dissolve  50  grams  of  ammonium 
phosphate  in  1,000  cubic  centimeters  of  distilled  water. 

Ammonium  Molybdate. — Solution  No.  I. — Place  in  a  beaker 
100  grams  of  85  per  cent,  molybdic  acid,  mix  it  thoroughly 
with  240  cubic  centimeters  of  distilled  water,  add  140  cubic 
centimeters  of  ammonium  hydroxide,  specific  gravity  0.90, 
filter,  and  add  60  cubic  centimeters  of  nitric  acid,  specific 
gravity  1.42. 

Solution  No.  2. — Mix  400  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  960  cubic  centimeters  of  distilled 
water. 

When  the  solutions  are  cold,  add  solution  No.  I  to  solution 
No.  2,  stirring  constantly;  then  add  o.i  gram  of  ammonium 
phosphate  dissolved  in  10  cubic  centimeters  of  distilled  water, 
and  let  stand  at  least  24  hours  before  using. 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel   (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 
21 


Acid  Ammonium  Sulphate. — Mix  50  cubic  centimeters  of 
sulphuric  acid,  specific  gravity  1.84,  and  950  cubic  centimeters 
of  distilled  water,  and  when  cold  add  15  cubic  centimeters  of 
ammonium  hydroxide,  specific  gravity  0.90.  Use  at  a  tem- 
perature of  80°  C. « 

Standard  Potassium  Permanganate. — Dissolve  0.35  gram 
of  potassium  permanganate  in  1,000  cubic  centimeters  of  dis- 
tilled water,  and  standardize  by  using  Bureau  of  Standards 
sodium  oxalate.1  Adjust  the  solution  so  that  i  cubic  centi- 
meter is  equivalent  to  0.02  per  cent,  vanadium  on  the  basis 
of  a  2.5  gram  sample. 

The  factor  Na2C2O4 — >  V  =  0.7612  (using  the  1913  atomic 
weights). 

METHOD. 

In  a  300  cubic  centimeter  Krlenmeyer  flask  dissolve  2.5 
grams  of  steel  in  50  cubic  centimeters  of  the  nitric  acid.  Heat, 
and  while  boiling  add  6  cubic  centimeters  of  the  potassium 
permanganate  solution  and  continue  boiling  until  manganese 
dioxide  precipitates.  Dissolve  the  precipitate  by  additions  of 
the  sodium  bisulphite  solution  and  boil  until  clear  and  free 
from  oxides  of  nitrogen.  Add  5  cubic  centimeters  of  the 
ammonium  phosphate  solution  and  10  grams  of  ammonium 
nitrate,  heat  to  boiling,  remove  from  the  plate  and  add  im- 
mediately 50  cubic  centimeters  of  the  ammonium  molybdate 
solution.  Let  stand  I  minute,  shake  or  agitate  for  3  minutes, 
filter  the  supernatant  liquid  by  suction  through  an  asbestos 
filter,  and  wash  three  times  with  the  hot  acid  ammonium  sul- 
phate solution.  The  flask  containing  the  bulk  of  the  precipi- 
tate is  then  set  under  the  funnel  fitted  into  a  bell- jar  filter 
and  the  asbestos  pad  is  treated  with  successive  small  portions 
of  hot  sulphuric  acid,  specific  gravity  1.84.  The  solution  is 
then  heated  until  the  precipitate  is  completely  dissolved,  a 
few  drops  of  the  nitric  acid  added,  and  the  heating  continued 
until  copious  fumes  of  sulphuric  acid  are  evolved.  Cool  the 
solution,  add  hydrogen  peroxide  in  small  quantities,  with  vig- 

1  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


319 

orous  shaking  after  each  addition,  until  the  solution  takes  on  a 
deep  brown  color.  Replace  flask  on  the  hot  plate,  fume  for  4 
or  5  minutes,  cover  the  flask,  cool,  add  100  cubic  centimeters 
of  distilled  water,  heat  to  80°  C.  and  titrate  with  the  stand- 
ard potassium  permanganate  solution  to  a  permanent  pink 
color. 

NOTE. 

If,  after  the  addition  of  hydrogen  peroxide  and  subsequent  heating, 
the  solution  does  not  take  on  a  clear  green  or  blue  color,  it  should  be 
heated  until  fumes  of  sulphuric  acid  are  evolved  to  rid  of  any  traces 
of  nitric  acid  which  interferes  with  the  reduction,  then  cooled  and  the 
treatment  with  hydrogen  peroxide  repeated. 

Determination  of  Vanadium  by  the  Ether  Extraction  Hydro- 
chloric Acid  Reduction  Method. 

(Routine.) 
SOLUTIONS  REQUIRED. 

Hydrochloric  Acid. — Mix  600  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  and  400  cubic  centimeters 
of  distilled  water. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Sulphuric  Acid. — Mix  500  cubic  centimeters  of  sulphuric 
acid,  specific  gravity,  1.84,  and  500  cubic  centimeters  of  dis- 
tilled water. 

Potassium  Permanganate. — Dissolve  25  grams  of  potassium 
permanganate  in  1,000  cubic  centimeters  of  distilled  water. 

Standard  Potassium  Permanganate. — Dissolve  0.35  gram  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  dis- 
tilled water,  and  standardize  by  using  Bureau  of  Standards 
sodium  oxalate.1  Adjust  the  solution  so  that  I  cubic  centi- 
meter is  equivalent  to  0.02  per  cent,  vanadium  on  the  basis  of 
a  2.5-gram  sample. 

1  Circular  No.  40.  Bureau  of  Standards,  Oct.  i,  1912. 


320 

The  factor  Na2C2O4  —  >  ¥  =  0.7612  (using  the  1913  atomic 
weights). 

METHOD. 

.  In  a  150  cubic  centimeter  beaker  dissolve  2.5  grams  of  the 
steel  in  50  cubic  centimeters  of  the  hydrochloric  acid,  add 
small  portions  of  the  nitric  acid  to  oxidize  the  iron,  and  heat 
to  expel  the  oxides  of  nitrogen.  Cool,  and  transfer  the  solu- 
tion into  an  8-ounce  separatory  funnel,  rinsing  the  beaker  with 
small  portions  of  the  hydrochloric  acid.  Add  50  cubic  centi- 
meters of  ether,  shake  for  5  minutes,  let  settle  for  i  minute, 
and  then  draw  off  lower  clear  solution  into  another  8-ounce 
separatory  funnel.  Add  10  cubic  centimeters  of  hydrochloric 
acid,  specific  gravity  1.20,  -to  the  solution  in  the  first  separa- 
tory funnel,  shake  thoroughly,  allow  to  settle  for  i  minute, 
and  then  draw  off  the  lower  clear  solution  into  the  second 
separatory  funnel.  To  the  combined  solutions  in  the  second 
separatory  funnel  add  50  cubic  centimeters  of  ether,  shake 
for  5  minutes,  let  settle  for  I  minute,  and  then  draw  off  the 
clear  layer  into  a  150  cubic  centimeter  beaker.  Heat  the 
aqueous  solution  gently  to  expel  the  ether,  add  25  cubic  centi- 
meters of  the  sulphuric  acid,  and  heat  until  copious  fumes  are 
evolved.  Cool,  dilute  with  25  cubic  centimeters  of  water,  add 
a  slight  excess  of  the  potassium  permanganate  solution,  and 
boil.  Add  15  cubic  centimeters  of  hydrochloric  acid,  specific 
gravity  1.20,  and  heat  to  fuming  for  10  minutes.  Cool,  add 
loo  cubic  centimeters  of  water,  heat  to  80°  C.,  and  titrate 
with  the  standard  potassium  permanganate  solution  to  a  per- 
manent pink  color. 

NOTE. 

In  heating  the  solution  to  expel  oxides  of  nitrogen  care  should  be 
taken  not  to  boil. 


CHROMA-  VANADIUM 
Determination  of  Carbon. 

See  the  Determination  of  Carbon  in  Plain  Carbon  Steel  by 
the  Direct  Combustion  Method.1 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


321 

Determination  of  Manganese. 

See  the  Determination  of  Manganese  in  Chrome-Nickel 
Steel  by  the  Zinc  Oxide  Bismuthate  Method. 

See  the  Determination  of  Manganese  in  Chrome-Nickel 
Steel  by  the  Modified  Bismuthate  Method. 

Determination  of  Phosphorus. 

See  the  Determination  of  Phosphorus  in  Vanadium  Steel  by 
the  Modified  Molybdate  Magnesia  Method. 

See  the  Determination  of  Phosphorus  in  Vanadium  Steel  by 
the  Modified  Alkalimetric  Method  (Routine). 

Determination  of  Sulphur. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Oxidation  Method.1 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Evolution-Titration  Method  (Routine). 

NOTES. 

The  Evolution-Titration  Method  should  not  be  used  with  steels 
containing  appreciable  amounts  of  tungsten,  or  of  copper  or  other 
metals  precipitated  by  hydrogen  sulphide  from  acid  solutions. 

The  annealing  of  the  steel  drillings  has  been  found  by  a  number 
of  investigators  to  increase  the  degree  of  refinement  of  the  method. 

Determination  of  Silicon. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Nitro-Sulphuric  Method. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Sulphuric  Acid  Method  (Optional). 

Determination  of  Chromium  by  the  Fusion  Method. 

SOLUTIONS  REQUIRED. 

Sulphuric  Acid.— Mix  1,000  cubic  centimeters  of  sulphuric 
acid,  specific  gravity  1.84,  and  3,000  cubic  centimeters  of  dis- 
tilled water. 

1  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  %oi. 


322 

Sodium  Carbonate. — A  saturated  solution;  approximately 
60  grams  of  sodium  carbonate  and  100  cubic  centimeters  of 
distilled  water. 

Magnesium  Carbonate. — Ten  grams  of  finely  divided  mag- 
nesium carbonate  suspended  in  100  cubic  centimeter  of  distilled 
water. 

Barium  Carbonate. — Ten  grams  of  finely  divided  barium 
carbonate  suspended  in  100  cubic  centimeters  of  distilled 
water. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Potassium  Ferricyanide  Indicator. — Dissolve  o.i  gram  of 
potassium  ferricyanide  in  50  cubic  centimeters  of  distilled 
water  (see  notes). 

Standard  Potassium  Bichromate. — Dissolve  5  grams  of 
potassium  bichromate  in  1,000  cubic  centimeters  of  distilled 
water,  standardize  against  pure  ferrous  ammonium  sulphate, 
and  adjust  to  tenth-normal. 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammonium 
sulphate  in  900  cubic  centimeters  of  distilled  water  and  100 
cubic  centimeters  of  sulphuric  acid  (i:  i).  The  strength  of 
this  solution  should  be  expressed  in  terms  of  chromium  and 
vanadium. 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask,  covered,  dissolve 
i  gram  of  steel  in  50  cubic  centimeters  of  the  sulphuric  acid 
(see  notes).  When  completely  dissolved,  add  50  to  75  cubic 
centimeters  of  hot  water,  then  gradually  the  sodium  carbonate 
solution  until  near  neutrality,  and  then  add  an  excess  of  the 
magnesium  carbonate  suspension  (see  notes),  and  boil  vigor- 
ously for  15  minutes,  with  the  cover  on,  adding  fresh  portions 
of  the  carbonate  suspension  during  this  time,  so  that  there  is 
present  in  the  solution  at  the  end  of  the  operation  an  excess 
of  2  to  3  grams  of  the  carbonate.  Let  settle  and  pour  the 
supernatant  liquid  on  a  rapid  filter,  washing  by  decantation 


3^3 

twice  with  cold  water,  pouring  the  washings  through  the  filter. 
Transfer  the  filter  to  a  platinum  crucible  and  after  burning 
off  the  paper,  fuse  the  residue  for  10  minutes  with  a  mixture 
of  5  grams  of  sodium  carbonate  and  0.25  gram  of  potassium 
nitrate.  Dissolve  the  fusion  in  water,  transfer  to  a  beaker, 
add  2  cubic  centimeters  of  3  per  cent,  hydrogen  peroxide,  boil 
a  few  minutes  and  filter.  Add  20  cubic  centimeters  of  the 
sulphuric  acid,  stir  vigorously,  cool  and  titrate  against  the 
standardized  ferrous  sulphate  solution,  using  the  potassium 
ferricyanide  as  outside  indicator,  or  add  at  once  a  measured 
amount  (in  excess)  of  the  ferrous  sulphate  solution  and 
titrate  back  against  the  standard  potassium  bichromate  solu- 
tion, using  the  same  indicator. 

From  the  number  of  cubic  centimeters  of  the  standard  fer- 
rous sulphate  solution  required  deduct  the  number  of  cubic 
centimeters  of  the  standard  ferrous  sulphate  solution  equiva- 
lent to  the  vanadium  in  the  steel,  as  determined  by  the  Phos- 
phomolybdate  Precipitation  Method  for  Vanadium  Steel,  and 
the  result  will  be  the  number  of  cubic  centimeters  of  the 
standard  ferrous  sulphate  solution  equivalent  to  the  chromium 
in  the  steel. 

NOTES. 

The  solution  of  the  steel  may  be  in  hydrochloric  acid,  specific 
gravity  1.20  or  any  other  desired  strength,  adjusting  the  amount  of 
acid  used  to  ?,void  a  large  excess  being  present. 

Barium-carbonate  suspension  may  be  substituted  for  the  mag- 
nesium-carbonate suspension  when  hydrochloric  acid  is  used  as  solvent. 

All  hydrogen  peroxide  must  be  destroyed  by  boiling  before  acidi- 
fying, otherwise  chromic  acid  will  be  reduced  at  this  stage. 

The  insoluble  residue  remaining  after  extraction  of  the  fusion 
should  be  examined  for  chromium. 

The  potassium  ferricyanide  indicator  should  be  prepared  fresh  on 
the  day  it  is  used. 

The  ferrous  sulphate  solution  should  be  standardized  on  the  day 
it  is  used. 

In  titrating  with  the  ferrous  sulphate  solution  it  is  convenient  to 
divide  the  solution,  roughly  titrate  one  portion,  add  the  other  and 
finish  carefully. 


324 

Determination  of  Chromium  by  the  Chlorate  Method. 

(Routine.) 
SOLUTIONS  REQUIRED. 

Nitric  Acid. — Mix  1,000  cubic  centimeters  of  nitric  acid, 
specific  gravity  1.42,  and  1,200  cubic  centimeters  of  distilled 
water. 

Potassium  Ferricyanide  Indicator. — Dissolve  o.i  gram  of 
potassium  ferricyanide  in  50  cubic  centimeters  of  distilled 
water  (see  notes). 

Standard  Potassium  Bichromate. — Dissolve  5  grams  of 
potassium  bichromate  in  1,000  cubic  centimeters  of  distilled 
water,  standardize  against  pure  ferrous  ammonium  sulphate, 
and  adjust  to  tenth-normal. 

Standard  Potassium  Permanganate. — Dissolve  0.5  gram  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  distilled 
water.  Standardize  by  using  Bureau  of  Standards  sodium 
oxalate.1  Adjust  the  solution  so  that  I  cubic  centimeter  is 
equivalent  to  0.05  per  cent,  vanadium  on  the  basis  of  a  I  gram 
sample. 

The  factor  Na2C2O4 — >  V  =  0.7612  (using  the  1913  atomic 
weights). 

Ferrous  Sulphate. — Dissolve  25  grams  of  ferrous  ammonium 
sulphate  in  900  cubic  centimeters  of  distilled  water  and  100 
cubic  centimeters  of  sulphuric  acid  ( I :  I ) .  The  strength  of 
this  solution  should  be  expressed  in  terms  of  chromium  and 
vanadium. 

METHOD. 

In  a  300  cubic  centimeter  Erlenmeyer  flask  dissolve  I  gram 
of  the  steel  in  30  cubic  centimeters  of  the  nitric  acid,  and 
evaporate  rapidly  to  approximately  one-half  volume.  Add  50 
cubic  centimeters  of  nitric  acid,  specific  gravity  1.42,  and  I 
gram  of  sodium  chlorate  (see  notes).  Evaporate  by  boiling 
to  one-half  volume,  dilute  with  100  cubic  centimeters  of 
water  and  filter  off  the  manganese  dioxide,  using  suction, 

1  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


325 

washing  with  hot  water.  Cool  the  solution  to  room  tempera- 
ture and  complete  the  determination  by  either  of  the  follow- 
ing procedures : 

1.  Titrate  against  the  ferrous  sulphate  solution,  using  the 
potassium    ferricyanide    solution    as    outside    indicator    (see 
notes).    From  the  number  of  cubic  centimeters  of  the  ferrous 
sulphate  solution  required  deduct  the  number  of  cubic  centi- 
meters of  the  ferrous  sulphate  solution  equivalent  to  the  va- 
nadium in  the  steel,  as  determined  by  the  Phosphomolybdate 
Precipitation  Method  for  Vanadium  Steel,  and  the  result  will 
be  the  number  of  cubic  centimeters  of  the  ferrous  sulphate 
solution  equivalent  to  the  chromium  in  the  steel. 

2.  Titrate  against  the  ferrous  sulphate  solution,  using  the 
potassium    ferricyanide    solution    as    outside    indicator    (see 
notes).    Cool  to  15°  C.  and  titrate  against  the  standard  potas- 
sium permanganate  solution  to  a  pink  color  permanent  for  10 
seconds.     Deduct  the  number   of   cubic   centimeters  of  the 
standard  potassium  permanganate  solution  consumed,  which 
gives  a  direct  measure  of  the  vanadium  content  of  the  steel, 
from   the   first   titration;    the    remainder   will    represent   the 
chromium  content  of  the  steel. 

NOTES. 

The  potassium-ferricyanide  indicator  should  be  prepared  fresh  on 
the  day  it  is  used. 

The  ferrous-sulphate  solution  should  be  compared  on  the  day  it 
is  used  with  the  standard  potassium-permanganate  or  potassium- 
bichromate  solutions. 

Potassium  chlorate  may  be  used  as  oxidizing  agent  in  the  place  of 
sodium  chlorate. 

In  titrating  with  the  ferrous-sulphate  solution  it  is  convenient  to 
divide  the  solution,  roughly  titrate  one  portion,  add  the  other  and 
finish  carefully. 

Determination  of  Vanadium. 

See  the  Determination  of  Vanadium  in  Vanadium  Steel  by 
the  Phosphomolybdate  Precipitation  Method. 


326 

Determination  of  Vanadium  by  the  Ether  Extraction  Hydro- 
chloric Acid  Reduction  Method. 

(Routine.} 
SOLUTIONS  REQUIRED. 

Hydrochloric  Acid. — Mix  500  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1:20,  and  500  cubic  centimeters  of 
distilled  water. 

Standard  Potassium  Permanganate. — Dissolve  2  grams  of 
potassium  permanganate  in  1,000  cubic  centimeters  of  dis- 
tilled water,  and  standardize  by  using  Bureau  of  Standards 
sodium  oxalate.2  Adjust  the  solution  so  that  I  cubic  centi- 
meter is  equivalent  to  o.io  per  cent,  vanadium  on  the  basis  of 
when  a  5-gram  sample. 

The  factor  Na2C2O4 — >  V  =  0.7612  (using  the  1913  atomic 
weights). 

METHOD. 

In  a  150  cubic  centimeter  beaker,  dissolve  5  grams  of  the 
steel  in  60  cubic  centimeters  of  the  hydrochloric  acid,  add 
small  portions  of  nitric  acid,  specific  gravity  1.42,  to  oxidize 
the  iron,  avoiding  an  excess,  and  heat  to  expel  the  oxides  of 
nitrogen.  Cool,  and  transfer  the  solution  into  an  8-ounce 
separatory  funnel,  rinsing  the  beaker  with  small  portions  of 
the  hydrochloric  acid.  Add  50  cubic  centimeters  of  ether, 
shake  for  5  minutes,  let  settle  for  i  minute,  and  then  draw  off 
lower  clear  solution  into  another  separatory  funnel.  Add  10 
cubic  centimeters  of  hydrochloric  acid,  specific  gravity  1.20, 
to  the  solution  in  the  first  separatory  funnel,  shake  thoroughly, 
allow  to  settle  for  i  minute,  and  then  draw  off  the  lower  clear 
solution  into  the  second  separatory  funnel.  To  the  combined 
solution  in  the  second  separatory  funnel  add  50  cubic  centi- 
meters of  ether,  shake  for  5  minutes,  let  settle  for  i  minute, 
and  then  draw  off  the  clear  layer  into  a  150  cubic  centimeter 
beaker.  Heat  the  aqueous  solution  gently  to  expel  the  ether, 
evaporate  to  approximately  one- fourth  original  volume,  add 

2  Circular  No.  40,  Bureau  of  Standards,  Oct.  i,  1912. 


327 

O.5  gram  of  potassium  chlorate  and  boil  down  to  a  volume  of 
10  cubic  centimeters.  Add  25  cubic  centimeters  of  hydro- 
chloric acid,  specific  gravity  1.20,  and  again  evaporate  to  10 
cubic  centimeters.  Add  20  cubic  centimeters  of  sulphuric 
acid,  specific  gravity  1.84,  and  evaporate  until  copious  fumes 
of  sulphuric  acid  are  evolved.  Cool,  dilute  with  water  to  100 
cubic  centimeters  volume,  and  titrate  against  the  standard 
potassium  permanganate  to  a  pink  color  permanent  for  10 
seconds.  Deduct  the  chromium  blank  and  the  remainder  is 
equivalent  to  the  vanadium  content  of  the  steel. 

NOTE. 

If  much  chromium  relative  to  the  vanadium  is  present  the  result 
will  be  high  due  to  the  oxidation  of  a  portion  of  the  chromium  by  the 
permanganate,  and  should  be  corrected  by  a  blank  which  varies  with 
the  amount  of  the  chromium  present.  This  blank  is  conveniently  made 
by  putting  a  suitable  amount  of  a  chrome  or  chrome-nickel  steel, 
free  from  vanadium,  through  the  above  process.  By  using  varying 
amounts  of  this  steef,  so  as  to  vary  the  chromium  correspondingly,  a 
curve  may  be  constructed  showing  the  relation  between  amount  of 
chromium  present  and  the  amount  of  blank,  and  this  curve  can  then 
be  used  in  all  subsequent  work. 


SIUCO-MANGANESE; 

Determination  of  Carbon. 

See  the  Determination  of  Carbon  in  Plain  Carbon  Steel  by 
the  Direct  Combustion  Method.1 

Determination  of  Manganese. 

See  the  Determination  of  Manganese  in  Plain  Carbon  Steel 
by  the  Bismuthate  Method.  .  ' 

See  the  Determination  of  Manganese  in  Plain  Carbon  Steel 
by  the  Persulphate  Method  (Routine). 

Determination  of  Phosphorus. 

See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Molybdate  Magnesia  Method. 

i  Standard  Methods  for  Chemical  Analysis  of  Plain  Carbon  Steel  (Serial  Designa- 
tion: A  33),  1915  Year-Book,  p.  201. 


328 


See  the  Determination  of  Phosphorus  in  Plain  Carbon  Steel 
by  the  Alkalimetric  Method  (Routine). 

Determination  of  Sulphur. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Oxidation  Method. 

See  the  Determination  of  Sulphur  in  Plain  Carbon  Steel  by 
the  Evolution-Titration  Method  (Routine). 

NOTES. 

The  Evolution-Titration  Method  should  not  be  used  with  steels 
containing  appreciable  amounts  of  tungsten,  or  of  copper  or  other 
metals  precipitated  by  hydrogen  sulphide  from  acid  solutions. 

The  annealing  of  the  steel  drillings  has  been  found  by  a  number 
of  investigators  to  increase  the  degree  of  refinement  of  the  method. 

Determination  of  Silicon. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Nitro-Sulphuric  Method. 

See  the  Determination  of  Silicon  in  Plain  Carbon  Steel  by 
the  Sulphuric  Acid  Method  (Optional). 

CONVERSION  TABLE  USED  IN  WATER  ANALYSIS. 


Factor 

Na20 

to  Na2SO.t 

2.29 

S03 

"         " 

J-775 

Cl 

'•   NaCl 

1.6486 

NaCl 

"    Na2O 

0.53028 

Na2O 

V    NaCl 

1.8858 

Na20 

"    Na2CO3 

1.71 

CaO 

"    CaC03 

1.7844 

MgO 

"    MgC03 

2.1 

S03 

"    CaSO4 

1-7 

S03 

11    MgS04 

i-5 

Cl 

"    CaCl2- 

1-563 

MgO 

"    MgCl2 

2.4 

Cl 

"    MgCl, 

1-34 

MgO 

"    Mg 

0.6 

MgO 

"    MgS04 

3-o 

CaS04 

"    CaCO3 

0.736 

Mg2P20T 

"    MgO 

0.36 

BaSO4 

"   S 

0.137 

BaSO4 

"  S03 

0-343 

Factor 

AgCl 

to    Cl 

0.247 

CaC03 

"     CO2 

°-439 

MgC03 

»     C02 

0.521 

Na2S04 

"     Na2O 

0.4366 

CaO 

"     CaCl2 

1.9777 

CaO 

"     CaS04 

2.4 

CaS04 

"     CaO 

0.412 

Na2C03 

•'     C02 

0.415 

SO3 

"     CaS04 

1.7005 

CaO 

"     CaCO3 

1.7844 

NgO 

"     NgC03 

2.0912 

Na20 

"     NaCl 

1.8858 

Cl 

"     NaCl 

1.6486 

CaC03 

"     C02 

0.4396 

MgC03 

'•     C02 

0.5218 

NaCl 

"     Na 

0-3934 

Na 

"     Na20 

1-3478 

Na2O 

"     Na 

0.7419 

MgO 

V     Mg 

0.603 

Mg 

"     MgO 

1-657 

329 


TABLES  FOR  CALCULATING  ANALYSIS. 


Sought 

Found 

Factor 

Ag  

AgBr 

0-5744 

AgCl 

0.7527 

Ag2S 

0.8707 

Al  

A12O3 

0.5303 

As    

As2S3 

0.0093 

As2S5 

0.4834 

(NH4MgAsO02.H2O 

0.3938 

Mg2As->O7 

0.4828 

Mg2P26r 

0.6736 

BaS04 

O.2I4I 

As2O3    

As2S3 

0.8042 

As.Ss 

0.6381 

(NH4MgAsO4)2.H2O 

0.5198 

MgaAsaOr 

0.6373 

Mg2P2O7 

0.8891 

BaSO4 

0.2827 

As2O8  

As2S3 

0.9342 

As2Ss 

0.7412 

(NH4MgAsO4)2.H20 

0.6038 

Mg^SaOi 

0.7403 

Mg2P207 

1.0328 

BaSO4 

0.3284 

AsOa  

As2S3 

0.9992 

As2S5 

0.7928 

(NH4MgAsO4)2.H2O 

0.6458 

Mg2As2O7 

0.7918 

Mg2P2Oi 

1.1046 

BaSO4 

0.3512 

AsO*  

As2S3 

I.I29I 

As2S0 

0.8959 

(NH4MgAsO4)2.H2O 

0.7298 

Mg2As2O7 

0.8947 

Mg2P2O7 

1.2483 

BaSO* 

0.3969 

Ba    

BaC03 

0.6961 

BaCrO4 

0.5420 

BaS04 

0.5886 

BaSiF6 

0.4906 

BaCO3    

BaCr04 

0.7787 

Ba(NOi), 

BaCr04 

I.03I4 

BaO   

BaC03 

0-7771 

BaCrO4 

0.0051 

BaSO4 

0.6571 

BaSiF6 

0.5478 

Be  

BeO 

0.3626 

Bi    

Bi2O3 

0.8968 

BiOCl 

O.8OI9 

Bi2S3 

0.8125 

Br    

AgBr 

0.4255 

I,og 

.75924 
.87665 
.93986 
.72455 
.78480 
.68431 
.59528 
.68375 
.82837 
.33070 
.90538 
.80489 
.71586 
.80433 
.94895 
45128 

.97044 
.86995 
.78092 
.86939 
.OI4OI 

.51634 

.99965 
.89916 
.81013 
.89860 
.04322 

•54555 

.05275 
.95226 
.86323 
.95170 
.09632 
.59865 
.84266 
•73401 
.76981 
.69077 
•89135 
.01342 
.89049 
.78184 
.81764 
.73860 

•55937 
.95209 
.90414 
.90985 
.62895 


330 


TABLES  FOR  CALCULATING  ANALYSIS.— (Continued) 

Sought  Found 

C    CO2 

CN   AgCN 

C02   CaC03 

CaO 

MgO 

CO3  ... CO2  • 

Ca    CaCO3 

CaO 

CaSO4 

CaCOs CaS04 

CaO   CO2 

CaCO3 

CaSO4 

CaSO4.2H2O 

CaSO.,   BaS04 

Cd   CdO 

CdS 

CdSO4 

CdO  CdS 

Ce  Ce2O3 

CeO2 

Cl Ag 

AgCl 

Co   Co3O4 

CoSO4 

CoO  Co 

CoSO4 

Cr  Cr2O3 

PbCrO* 

Cr2O3  PbCrO4 

CrOs Cr2O3 

PbCrO4 

Cr04   Cr203 

PbCrO4 

Cs  Cs2S04 

Cu   CuO 

CUaS 

CuFeS2   Cu2S 

Cu2O CuO 

CuO  Cu 

Cu2S 
CuSO4.sH2O  Cu 

Cu2S 

Er  Er2O3 

F    , ' CaF2 


Factor 

l*g 

0.2727 

•43573 

0.1944 

.28860 

04394 

.64289 

0.7839 

•89425 

I.09O2 

.03750 

1.3636 

.13470 

0.4008 

.60291 

0.7149 

-85427 

0.2947 

46932 

0.7352 

.86641 

1-2757 

.10575 

0.5606 

.74864 

O4I2I 

.61505 

0.3259 

.51312 

0.5833 

.76588 

0.8754 

.94220 

0-7779 

.89000 

0.5391 

.73166 

0.8886 

.94870 

0.8539 

.93139 

0.8140 

.91064 

0.3285 

.51650 

0.2473 

.39315 

0-7344 

.86595 

0.3804 

.58024 

1.2712 

.10421 

04837 

.68456 

0.6847 

.83550 

0.1613 

.20776 

0.2356 

.37226 

I-3I53 

.11902 

0.3099 

49128 

1.5255 

.18341 

0-3595 

.55567 

0-7344 

.86596 

0.7990 

•90255 

0.7987 

.90238 

2.3056 

.36279 

0.8995 

.95400 

1.2516 

.09745 

0.9996 

.99983 

3-9267 

.59403 

3-1362 

49641 

0.9737 

.94136 

0.4870 

.68756 

TABLES  FOR  CALCULATING  ANALYSIS.—  (Continued) 

Sought  Found  Factor  I/>g 

Fe    Fe2OG  0.6996  .84482 

FeO    Fe  1.2863  -10935 

Fe2O6  0.8999  .95417 

Fe2O3  Fe  1.4295  .15518 

FePO4  0.5294  .72375 

FeS2  Fe2O6  1.5022  .17674 

H H2O  0.119  .04869 

HBr  . AgBr  0.4309  .63439 

HC1 AgCl  0.2543  40532 

HJ    AgJ  0.5448  .73626 

HNO3 NH4C1  1.1781  .07117 

(NHOJPtCl.  0.2842   '  45363 

NO  2.0989  .32199 

Pt  0.6473  .81113 

H2SOi   BaSO4  0.4201  .62331 

Hg HgCl  0.8493  .92904 

HgS  0.8617  .93535 

J AgJ  0.5405  .73282 

PdJ2  0.7046  .84795 

K  KC1  0.5248  .71999 

KC1O4  0.2825  .45097 

K2PtCl6  0.1612  .20730 

K2SO4  0.4491  .65231 

Ft  0.4019  .60417 

K2O  KC1  0.6320  .80074 

KC1O4  0.3402  .53172 

K2PtCl6  0.1941  .28805 

K2SO4  0.5408  .73306 

Pt  0.4841  .68492 

K2SO,  BaS04  0.7468  .87318 

La La2O3  0.8527  .93078 

Mg  MgO  0.6036  .78073 

MgzPaOi  0.2188  -33999 

MgCOo  Mg2P2O7  0.7576  .87945 

MgO  Mg2P2Oi  0.3625  .55926 

Mn   Mn3O4  0.7205  .85764 

Mn2P2Or  0.3873  .58807 

MnS  0.6315  .80034 

MnCO3  Mn3O4  1.5066  .17798 

MnO  Mn3O4  0.9301  .96854 

MnS  0.8152  .91124 

Mo  MoO3  0.6667  .82391 

MoS2  0.5096  .77788 

N NH4C1  0.2623  .41885 

(NH4)2PtCl«  0.06329  .80131 

Pt  0.1441  .15881 

NH3  0.8235  .91566 


\  332 


TABLES  FOR  CALCULATING  ANALYSIS.—  (Continued) 


Sought  Found 

NH8    ......................     NH4C1 

(NH4)2PtCl6 

Pt 

NH4  .......................     NH4C1 

(NH4)2PtCl8 

Pt 
NO3    ....................  ...     NH.C1 

(NH4)2PtCl6 

NO 

Pt 
N2O5   ......................     NH4C1 

(NH4)2PtCl6 

NO 

Pt 
Na  ........................     NaCl 

Na2SO4 
Na2O  ......  ...............       NaCl 

Na2SO* 
Ni  .........................     NiO 

NiO    .......................     Ni 

P    .........................     Mg2P2O? 

(NH4)3PO4.i2MoO3 

P2O5.24MoO3 

P2O6     ......................       MgiPaOr 

(NH4)3PO4.i2MoO3 

P2O5.24MoO3 
PO4  .......................     Mg2P2O7 

(NH4)3PO4.i2MoO3 

P2O5.24MoO3 
P2O5  .......  ................     P 

Pb    ........................     PbCrO4 

PbO 

PbO2 

PbS 

PbSO4 
PbO   .......................     PbCrO4 

PbO2 

PbS 

PbSO4 
PbS  .......................     PbSCX 

Rb  ........................     Rb2SO4 

S  ..........................     BaSO4 

503  .......................     BaSO4 

504  .......................     BaSO* 

Sb  ..  .......................     Sb2O4 

Sb2S:j 


Factor 

0.3177 
0.07690 

0.1752 

0.3376 
0.08145 
0.1855 
1.1592 
0.2796 
2.0652 
0.6370 
1.0097 
0.2436 
1.7090 
0.5548 
0.3940 
0.3243 
0.5308 
0.4368 
0.7858 
1.2726 
0.2784 
0.01639 
0.01723 

0.6376 

0.03753 
0.03947 

0.8532 

0.05022 

0.05281 

2.3 

0.6405 

0.9282 

0.8660 

0.8658 

0.6829 

0.6901 

0.9330 

0.9328 

0.7357 

0.7888 

0.6402 

0.1373 

0.3429 

0.4114 

0.7898 

0.7142 

0.5999 


.50346 
.88592 

.24342 

.52844 
.91090 
.26840 
.06415 
.44661 
.31497 
.8041  1 

.00430 
.38666 
.25502 
.74416 

-59551 
.51092 

.72490 
.64031 
.89532 
.10468 
.44467 
.21448 
.23633 

.80457 

-57438 
.59623 

.93103 
.70084 
.72269 
.36172 
.80654 
.96765 
.93754 
.93743 
.83438 
.83889 
.96989 
.96978 
-86673 
.89695 
.80633 
.13769 
.53515 
.61427 
,89749 
.85382 


333 


TABLES  FOR  CALCULATING  ANALYSIS.— (Continued) 

Sought  Found  Factor  I,og 

SbzOs  V.     SbsO*  0.9475  .97656 

Sb2S3  0.8568  .93289 

Sb2S5  0.7198  .85718 

Sb2S3 Sb2O4  1.1058  .04367 

SeO2   Se  1.4040  .14737 

SeO3   , Se  1.6061  .20576 

Si  SiO2  0.4702  .67228 

SiO3   SiO2  1.2649  .10205 

Shd  SiO2  1-3973  -I453O 

SiO*   SiO2  1.5298  .18463 

Sn    SnO2  0.7881  .89657 

Sr  SrCO3  0.5936  .77350 

SrCCX  0.4771  .67859 

SrCOa    Sr(NO3)2  0.6973  -84344 

Sr(OH)2.8H20  0.5555  -74468 

SrS  1.2334  .09111 

SrS.Os  0.7391  .86869 

Sr(OH)2.8H20    Sr(N03)2  1.2553  .09876 

Sr(SH)2  1.7283  .23762 

SrS2O3  1.3305  -12401 

SrSO*    '. BaSO*  0.7868  .89584 

TeO2  Te  1.2508  .09718 

TeO3    Te  1.3762  .13867 

Th  Th(NO3)44H2O  0.4207  .62393 

ThO2  0.8700  -94399 

Ti TiO2  0.6007  .77866- 

U   Na2U2Ot  0.7511  .87568 

UO2  0.8817  .94532 

U3O8  0.8482  .92852 

W  WO3  0.7931  .89933 

Y   Y2O3  0.7876  .80631 

Zn  ZnO  0.8035  -90496 

ZnS  0.6710  .82675 

ZnO ZnS  0.8352  .92179 

ZnS  ZnO  I.I973  -07821 

ZnSO4.7H2O   ZnO  3-5329  -548i3 

ZnS  2.9507  .46992 

Zr  ZrO2  0.7300  .86864 


22 


334 

GAS  FACTORS. 

Grams  per  M3  X  43-7  =  grains  per  100  cubic  feet. 
Grams  per  M3  X  0.437  —  grains  per  cubic  foot. 
Grains  per  cubic  foot  X  2.288  =  grams  per  M3. 
Grains  per  100  cubic  feet  X  0.02288  =  grams  per  M3. 
Grams  per  cubic  foot  X  35-31  =  grams  per  M3. 
Grams  benzine  per  MS  X  0.0088  =  gallons  per  1,000  cubic  feet. 

I  MS  of  gas  at  o°  C.  and  760  millimeters  =  1.05505  M3  at  15°  C.  and 
760  millimeters. 

i  M3  of  gas  at  o°  C.  and  760  millimeters  =  1.0734  M3  at  20°  C.  and 
760  millimeters. 

i  MS  of  gas  at  15°  C.  and  760  millimeters  =  0.94782  MS  at  o°  C.  and 
760  millimeters. 

i  MS  of  gas  at  20°  C.  and  760  millimeters  =  0.93162  MS  at  o°  C.  and 
760  millimeters. 

Vapor  tension  divided  by  total  pressure  =  percentage  by  volume  of 
vapor  in  saturated  gas. 

22.37  liters  of  any  true  gas  or  vapor,  at  o°  C.  and  760  millimeters  pres- 
sure, has  a  weight  in  grams  equal  to  its  molecular  weight. 
Hence  it  follows  that  the  molecular  weight  of  any  gas  or  vapor 
divided  by  22.37  gives  the  weight  in  kilos  of  a  cubic  meter  of 
that  gas. 

Gas  at  o°  C.  X  1.367  =  volume  at  100°  C. 


335 


O    M     o 


8*  $  vS  *£• 

*-•     O     ^O   t*** 

•g    8   o    <T  o 


0*     0*    M     O*     0     M 


00      O      fO    *^ 

cs  oo  oo    ^o 


«  8 


o    o 


O     <0    «0 

«5    o 


Sf 


2 
!3 


s  s 


BOM          cs    c »    M 

•*J         Q        O  O        '^     O^      ^O 

s    o'  o'  M   o'  o   o   g\ 


B    ^1 
a    o  M 


III 


8  o  S 

T  °°.   1" 
\f>  ^t  -^  "if 

<N      O      w     •* 
to    ON    fO 

I 


336 


,4 


a* 

5 

<N                     00 

o 
H 

O                   00    vO 
fN                     vO 

"3 
0 

VO                    ro 
M     <N              to    rO            O 

^   "2"  Q         o    TJ-        o 
r^  vo     O    r^  00     O           (N 

|C   '  8  " 

c- 

O 
O     O                                 t^** 

o 

Cj       M       O     VO*     00*       M       M       |4. 

VO                   TJ- 

a 

vo                                  00 
M     to                  00    00     CO 
f<5    O                    *O  vO     O 

»o  o"   o  '   t>.  M   6   o   6 

3 

fj                   »O 

Q            rh    CS     io    ON 

to  g         o    o    ON  io 
co    M    g          t^   g    ^   o 
o    g    g         co  o    o    o 

to    O     O            O     O     O     O 

M     O     O     M     o*     O     O     O 

o 

a 

o 

00 
CO              O 

o            *>.  N 

.w 

M                  f^    VO       IO    VO 

0                    HH        M      00        10 

o    io  ro  o    t^  rf 

Q     M     O     ^t"  OO     O     fO    O 

Meter 

M                            VO       IO     t^. 

o         w    1-1  oo    10 

O     >O    rO    O     l^    rj- 

O    O  vo    <N    g    g    Q 

w     O     O     O     O     O     O     O 

3  13 


$  II  d 


<U      4j 

C    ri 
§    & 


J3<9  a    § 

«       VN        HH  5 

01  II    2   6    So 

sSl&s 

h4  .ti    ^  ^    °" 

II     5   r<   ^     C 


* 


- 


(S  <o  ,|  tS  S 


C 


<s 

d 

tc 

o 

§ 

en 

2 

d  d  M 

SR 

1 

*> 

c 

10                ^ 

M     fO   f^                        i 
M     <N     W 

s 

M 

o 

O    O    fO 

Q 

1 

O 

M     0 

§  8  8  §     2 

?o  £~ 

0   0    0    0   M   '- 

1 

§^8  S 

£ 

>> 

0   M    o   0   M   0    0 

2 

o- 

*«? 

« 

H 

ON 

o 

W  VO   »O 

o    ^>  _S 

to 

«5 

St^vO 
<N    0 

*"*  H    <^ 

00 

O    (N    O    i-i    O 

G      •   \o 

h-1   CO               Tt" 

O   O  CO   ON 

cT 

'3      °      <N 

8 

Q  M  ^^ 

iyi 

W)     M        II 

fa 

O   O  Is*  O 

^-i 

£!}  to 

r/^ 

* 

O   O    O   O   *-i   ON        O 

\^ 

T^~  o    ^ 

£_, 

a 

'ft 

Q 

u:>  d    g 

^ 

fO 

^ 

""bo 

w 

<^ 

ll    II  »2 

.    t 

t—  1 

> 

HH 

3.8 

i—  i 

cs  vo 

bi)  So 

o 

i-i    to 

§10  O 

w 

N 

O  cs 

M  M  a* 

/*"S> 

•S 

w   O 

O   10  M  v£>   O 

D 

til 

rr1 

O    O    O   M   rj-vD 

0 

CO            MO 

•    rt 

B     w      C 

W 

06 

IO             M      « 

*—  I                         M 

3 

N" 

11| 

0 

w 

ft  &"J3 

fc 

10 

g 

TJ-    g)    rO 

^ 

?i*J 

> 

"q    M    co 

c/3 

1 

ON  rO       VO 

o  oo      co 

C^H 

II     II     II 

OO>HOOO»-I^O 

CO    ^f 

oo  o 

C 

o0 

II    II    II 

Sr"* 

bio 

M            CO^^ 

o 

cT 

M 

o       o  10  M 
o'  M'  d  1"  tA  6 

H         g» 

a 

i-i                 10  CO  t^ 
O                   Tt  O    <N 

!w 

^ 

£ 

O          ON  fO 

o"          oo" 

o 

VO 

M    *O 

a 

M'    O  00*    <O  O*. 

O  cs  1000 

O                Tt    I-I 

a 

M   O   O  ¥r  O5 
1-1    O^^o   ON 

O 

' 

338 


X 

a  § 

10    ON   t^    ^    t~» 
ON    CN     IO  00     t>.    T^- 

HH        CO      CN        M        0        M 

00 

£ 

ro 

P 

IO    O     <N     O     O     O 

o 

CN 

v>    C 

r^  co    -<t   ON  co 

CO 

CN 

A    3 

•<*•   N  co    r^  CN    10 

O    M  oo    O    O    O 

CN 

0 

CO 

C    w 

•  «N   o   o   o   o   o 

o 

M 

O 

M  S 

li 

10           00 

O    r*^  *O   co   vO    co 

CN      IO    »O    M      M      IO 

M 

8 

s* 

O    IO  CO      CO    M      CN 
OO              «O 

cO 

Tf 

EV 

V 

CO     ON    CN    vo     ON 

ON 

Q 

CN 

T*H              Q 

O     M     M     CN     ^t 

CO 

CN 

t*** 

c  Jj 

to'  CN     IO    M      O      M 

0 

{->. 

vO 

CO                  M 

G 

|| 

%  3-^  S?      ? 

ON 

CO 

% 

O 

O    rj-    O     CN     *••     CN 

O 

S 

M 

Is 

(N                     CO 

M     co                   ON    ON 

M 

i—, 
CO 

85 

IF 

~    £ 

t^     M       CN       M       O       O 

0 

co 

M 

§3   £?| 

vO 

O 

CO 

5 

$"  * 

CN     0     M     0     0     0 

0 

0 

X 

00    VO     rj-  CO 
CN      t^     CN      "sT 

S     V     CJ 

ON   10   CN    TJ- 

M 

CO 

o 

§    P«  fl 

VO     M    vo     O     O     O 

O 

t^ 

CO 

O 

°   5f  * 

co    co  VO     Tj-  OO 
VO      co    CO    ^      CN 

o   n-  o    o    o 

0 

1 

1 

*   &" 

M     O     O     O     O     O 

o 

o 

o 

imeter  =  14.2232  pounds  per 

'.2048  pound  per  square  foot. 
•  square  meter  =  0.091  gross 

OJ 

1 
II 

VH' 

3 

1 

n 

£ 

cu 

*  I 

cn 
.•           cu 

03 
1 

«     o 

a  -n 

cy   "S 

S    -s 

a>        .C 

IH 

s  s 

'•M                  O^ 

cu 

§ 

G              • 

ft 

I?  H 

cu            ON 
O            N 

0 

VH     ,J 

CU                 II 

3 

<u    cu 
cu 

IH                  1  1 

03 

3         J3 

M 

£  B 

o1        <-> 
en          ^C 

U 

«  g 

Ui 

CU                CU 

CU 

^                 Cti 

CU 

CU 

cn           2 

S     s 

1 

o 

"S     CU 

S  ft 

^ 

ro           tu 
^             Pn 

cu 

IH 

cu    cn 

«H         G 

?             CU 

03 

rt    o 

M        s 

& 

%z 

H.     en        • 
x-s     en      >> 

JS    °Q     u!     *3 

u 

cu 

1-1    -*2 

cu     qj 

o  o  ft  d 

ft 

a  S 

•-H     x'     en     CJ 

8 

X 

cu   o  ^2   S 

o 

O        Vs* 

c^J     ft    3     cn 

15 

fO 

^t 

&°as 

t«      N_^-                    lJ 

CN 

00      || 

fe     ON   £    £ 

o 

00      || 

ft    *>    TJ-  S 

o 

M      O 

cn     0    -    -g 

^     >>    li     S 

II 

ll     0 

Mi 

-    1  "I   "> 

*0 

0     cu 

§     ft    g     b^ 

c 

9    *-• 

t;  si  N  lr 

03  ,d 

§    ^ 

i  N  i  t 

J3     O 

J3     j_ 

D^    G 
en    '** 

en     Q^ 

«  II  &  £  g 

.              cn     J5     £ 

s_     cu 

e  C  4i  **  « 

&s 

1  * 
I 

cu  a 
ft  o 

"S  s 

o  2 

ft   bo 

M       M 

&|  n  §  a 

C     CL    cu  .1-1     cn 
O    So    C  —    cu 
-*-•     o    cu  -rj   ,d 

a  s  s  g 

*  J£Q 

HH   14    t^    ro 

339 


3     ! 
2       8 

4  o 


s§  I 

§  a  * 
&  §J  5 

a  o  H 
«  & 

o  9 

'*     M          . 

«  S   g 

£°  i 

^^  & 

"5   .ti     5 

z  3    8> 

s*i 

to  ^3      . 
o  H   f* 

w       J 

B  « 

^          c 

^     ^ 

<J      •& 

t 


•z.-z 

w  s 
-  = 


Calori 
er  mo 
lar  wt 
gra 


. 


..£2*  ii 

>  so.  il 
p  o*2  «j 


Icl 


Name  of 
gas  or  vapor 


n^OI^-^l- 
i/5  04   r»  w 


»/5\g   ON  O  T> 
1---00   1^  LO  P) 


^^SofofofofofS'SofSSofof  •CS'S  .'  2  >*S**SS  .'  '  i  .'  .'  ' 


N  u-j  10  ej  q  •<*•  q  i  q  vq  oq  q  «  IN  N  r-.  M    .  "?  9    •  9    •  °!  °°  9  N.  "°.  9?  9 


ON  co  co  o_ «-;  ir>  o<_  o_  r>- 10  co  o_oo_  •<£  i 


CO         W   CN   l-OD   T-  o    (S 

o    -r^roiD  <n\o  r>  cu 


8&4M:&*2&S8fc*§a&a  • 

O.  CT*  ON  co  cr\  •«£  04_  i-«_  n_  04_  co  t~;*O.>O_  O  uo    . 

04   ON*O  vOnr^CNOO^f^JNcO^iOOi^O 
04   CO  1/5--O  00    ON  CO  -<3-\O  00    CO  Tf 


.  o 

.  **> 


LO       M       OOCO^UTJCS 

MO    -00      •  •*  ON  uS  10^0  00 
-^       N         "-I         iilNPIM 


-.ncogN* 
d  d  o'  d  d  d  6  d  d  6  o'  o'  d  d  d  d  6  d  d  6  d  d  d  d  d  d  d  6  d  d  d  d  d  d  d 


°r  S  o?  ONO"  co  g'  F-  •*  «  oo  inx  '&  04 \o  co  o'  r^oo  o  ub  «'  K  i-f  1/5  -  vb"  F-  o> 

^x8o8S'S-Mt?Sx?!S-n2-<;2^22-8oT^coKgsoro^8<?2r:3'vS! 


ON  ON  to'o  vo  ••*•  t~» 

•^  rr  O   N  04   O\00  - 
t^  t^  10x0  ^0   uouoiO 


t^.  if)  O^  W  ^2  OO  OOOO  UOC4VO   CO^MVO   O  O^ 
^  iO  c'JOO   CO  (S  GO  *O  iO  ^  r^od  vO   iO  ^J-  cf^vC   •^•^ffOtOCS  »-*  C)   tOr^'^'>-«o6od  ^  10  M   COCO 


-*0\r^rOiO 


of?, 
d  d 


iS'fti 


.coo          .     .  i 

•H  •  •  •$ 

•66    •    •    "6 


00  «^^5    .10 

OOOOOOM 
o'  o'  o'    •  M 


:§°v<* 


1  ++-}- 


++ 


+++ 


04  04  M  04   ONX  vg  >T;cOi-i\O   *  «*>  "-1  •*  f*3  "-1   <*5<M   OOO   O   ONOO  OO  O  00  M  rf 


d  o'  o'  o'  o'  M  M  o«  04  o)  d  w  >->  oi  o'  M  «  CM  to 


•*  w  o'  o'  •- 


SM   ^-  1/5  t^OO  04   M   ( 

04    ON  OM-i   O4  UO  O    I 

M  00    II    04    «  O    t^  I 

M  10  up\q  o<  11  o\  i 

M  «'  p-i  d  04"  M  d  > 


g23^*«,«,'2=,»o«»SS 

a  u*o  u  cfu  cJcJcJcfo'u'tj  uu'o  o 


055 

' 


1st 
Pf 


o       » 

r  ill 


340 


-  *i    C 

88| 
<  §1 

O   * 


S  s  i 

§1  I 

£  S  "° 

^  H  fc 


*l 

4J     > 

|o 

h?      tfl 

*      & 


•i*. 

S2*e 


o6'3 

0  °  n 


RRJ,  ;28  : 


+ 1  I 


COM 


tOO^iOOxNlNNMTtOON  -^-00   >iQt-~ 
CO  Q    CO  IDvO    T  ^J"  ^d"  ^"OO    O    1/3OO    ^fMOCO 

OK  O  O  q  q  -  «  w  -;  ro  co  «s  to  co  co  co  Tr   .    .  \q  \o  to 

oicococococococococococococotococo  «   w"   6 


.  T  T  "1"  T  °.  N.  °J  °.  M.  "*.  °J  ( 

M   N   o"  00   •<9-cOcOcOcocOcOCOcOcOcOtOtOCOcOrOcoi 


i-iWTtN^Or^OvO  "O^O  vOvC\OrOO'OcOt^OO-^-t-i'-iO  cO^O  N  CO 
--rtt^N  1-1  lOCONOO  OsCOcOcOCOi-i  UOO  M  -^-CS  UOOO  <->  M  •-  f>)  ^O  O  CO 
,  i/-)  T}-\O  COM  r*.iOcOC4OOOOOOOO  COOO  M  co  tO  t^OO  ChMt-»Tt-cO^^O 


>  M  ci  Tt"  r^-vp  10  u*)  10  10 


i:: 


q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  19  10  •    •  o  o 

M  cs   CO  TJ-  IO\O  t^-CM  cO'i'U'iM  CS   rOcO1^  lO^O   T^-tHtHO      .     .cJcO 


•  q  o    •  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q  q    •    •  q  q  q  q  q 
.  pi  M     .  «'  CN  co  •<*•  in\d  cs  co  -*r  10  pj  co  Ti-yD  t-^od  cf»  O     .     .  M  *i  M  M  ei 


lOO  COCOOOO   uorOOOO   (OCOOOO   COOOOOO   lOO   O   OOOON>-i   O   UOOO  1O    . 
oor--CM3Nr-.Tf^  ooo  ioio<OMOO^b-^i-ioo^o  •'S-N  cs  r^oo  oo  r--  to  t^  10 
r-.>ococo>ot?.0"-.  CM  •»  f?  "?  <>•<»  <^  M  cooq  q  N  rt-  ^r  «  up  CTMTJ  co  >-<  co 
^-  GS  oi  cl  G\vo  co»-*od  u"5Tj-Moo  IOM  cfs^o  lococor^-r^r^coioc^TJ-r^1^- 


AUTHORITIES  AND  METHODS  OF  CALCULATION 
In  column  IX  the  figures  given  in  Hempel's  "Gas  Analysis,"  p.  375, 
were  selected  for  the  fundamental  weight  of  oxygen,  nitrogen,  hydrogen, 
carbonic  oxide  and  air. 

The  formula  used  for  the  conversion  to  English  units  is,— grams 
per  liter  at  o°  C.  and  760  mm.  -f  0.05922  =  pounds  per  cu.  ft.  at  60°  F. 
and  30"  pressure.  The  derivation  of  the  factor  employed  is 

28.316  X  0.0022046  Xso-oo  X  492 

29.9*  X  520 

The  weights  of  the  compound  gases  are  calculated  from  these  data  by 
Avogadro's  law. 

Column  IV  is  calculated  by  the  formula:  sp.  gr.  =  ft          ' 

and  the  figures  thus  obtained  agree  with  the  theoretical  formula, 

mol.  wt. 
SP'  «r'  =    -5TiT 

Columns  V  and  VI  are  taken  chiefly  from  Lunge's  "Coal  Tar  and 
Ammonia." 

Column  VII  is  from  Ganot's  "Physics,"  edition  1896,  page  445. 

Columns  X  and  XXIII  are  from  Julius  Thomsen's  "Thermo- 
chemical  Investigations,"  and  his  results  are  translated  into  English  units 
in  columns  XI-XII  and  XXIV-XXV. 

Columns  XIII  and  XVIII  are  calculated  on  the  assumption  that 
air  ==  20.9%    oxygen  +  79.1%    nitrogen  by  volume. 
air  =  23.13%  oxygen  -f-  76.87%  nitrogen  by  weight. 


Comparison  of  Degrees  Baume  with  Specific  Gravity,  American  Standard, 

for  Liquids  Lighter  than  Water.     Sp.  gr.  ±  ,        at  60°  F. 

1.30  -f-  B 


Deg. 
Baum6 

Specific  gravity 

o.o 

O.I 

O.2 

0.3 

0.4 

o.5 

0.6 

0.7 

0.8 

0.9 

10 

ii 

12 

I.OOOO 

0.9929 
0.9859 

0-9993 
0.9922 
0.9852 

0.9986 
0.9915 
0.9845 

0.9838 

0.9972 
0.9901 
0.9831 

0.9964 
0.9894 
0.9825, 

0.9818 

0.9950 
0.9880 
0.9811 

0-9943 
0.9873 
0.9804 

0.9936 
0.9886 
0.9997 

13 
14 
15 

0.9790 
0.9722 
0.9655 

0.9783 

0.9715 
0.9649 

0-9777 
0.9709 
0.9642 

0.9770 
0.9702 
0.9635 

0.9763 
0.9695 
0.9629 

0.9756 
0.9689 
0.9622 

0.9749 
0.9682 
0.9615 

0-9743 
0.9675 
0.9609 

0.9736 
0.9669 
0.9602 

0.9729 
0.9662 
0.9596 

16 

11 

0.9589 
0.9524 
0-9459 

0.9582 
0.9517 
°-9453 

0.9576 
0.95II 

0.9447 

0.9569 
0.9505 
0.9440 

0.9563 
0.9498 
0.9434 

0.9556 
0.9492 
0.9428 

0.9550 
0.9485 
0.9421 

0-9543 
0.9479 
0.9415 

0-9537 
0.9472 
0.9409 

0.9530 
0.9466 
0.9402 

19 
2O 

21 

0.9396 
0-9333 
0.9272 

0,9390 
0.9327 
0.9265 

0-9383 
0.9321 
0.9259 

0.9377 
0.9315 
0.9253 

0-9371 
0.9309 
0.9247 

0.9365 
0.9302 
0.9241 

0.9358 
0.9296 
0.9235 

0.9352 
0.9290 
0.9229 

0.9346 
0.9284 
0.9223 

0.9340 
0.9278 
0.9217 

22 
23 
24 

0.9211 
0.9150 
0.9091 

0.9204 
0.9144 
0.9085 

0.9198 
0.9138 
0.9079 

0.9192 
0.9132 
0.0073 

0.9186 
0.9126 
0.9067 

0.9180 
0.9121 
0.9061 

0.9174 
0.9115 
0.9056 

0.9168 
0.9109 
0.9050 

0.9162 
0.9103 
0.9044 

0.9156 
0.9097 
0.9038 

2? 

0.9032 
0.8974 
0.8917 

0.9026 
0.8969 
0.8912 

0.9021 
0.8963 
0.8906 

0.9015 
0.8957 
0.8900 

0.9009 
0.8951 
0.8895 

H 

0.8997 
0.8940 
0.8883 

0.8992 
0.8934 
0.8878 

0.8986 
0.8929 
0.8872 

0.8980 
0.8923 
0.8866 

28 
29 
30 

0.8861 
0.8805 
0.8750 

0.8855 
0.8799 
0.8745 

0.8850 
0.8794 
0.8739 

0.8844 
0.8788 
0.8734 

0.8838 
0.8783 
0.8728 

0.8833 
0.8777 
0.8723 

0.8827 
0.8772 
0.8717 

0.8822 
0.8766 
0.8712 

0.8816 
0.8761 
0.8706 

0.8811 
0.8755 
0.8701 

31 
32 

33 

0.8696 
0.8642 
0.8589 

0.8690 
0.8637 
0.8584 

0.8685 
0.8631 
0.8578 

0.8679 
0.8626 
0.8573 

0.8674 
0.8621 
0.8568 

0.8669 
0.8615 
0.8563 

0.8663 
0.8610 
0.8557 

0.8658 
0.8605 
0.8552 

0.8653 
0.8600 
0.8547 

0.8647 
0.8594 
0.8542 

34 
35 
36 

0.8537 
0.8485 
0.8434 

0.8531 
0.8480 
0.8429 

0.8526 
0.8475 
0.8424 

0.8521 
0.8469 
0.8418 

0.8516 
0.8464 
0.8413 

0.8511 
0.8459 
0.8408 

0.8505 
0.8454 
0.8403 

0.8500 
0.8449 
0.8398 

0.8495 
0.8444 
0.8393 

0.8490 
0.8439 
0.8388 

i 

39 

0.8383 
0.8333 
0.8284 

0.8378 
0.8328 
0.8279 

0.8373 
0.8323 
0.8274 

0.8368 
0.8318 
0.8269 

0.8363 
0.8314 
0.8264 

0.8358 
0.8309 
0.8260 

0.8353 
0.8304 
0.8255 

0.8348 
0.8299 
0.8250 

0.8343 
0.8294 
8.8245 

0.8338 
0.8289 
0.8240 

40 
4i 
42 

0.8235 
0.8187 
0.8140 

0.8230 
0.8182 
0.8135 

0.8226 
0.8178 
0.8130 

0.8221 
0.8173 
0.8125 

0.8216 
0.8168 
0.8121 

0.8211 
0.8163 

0.8116 

0.8206 
0.8159 
0.8111 

0.8202 
0.8154 
0.8107 

0.8197 
0.8149 
0.8102 

0.8192 
0.8144 
0.8097 

43 
44 
45 

0.8092 
0.8046 
0.8000 

5.8088 
0.8041 
0-7995 

0.8083 
0.8037 
0.7991 

0.8078 
0.8032 
0.7986 

0.8074 

0.8028 
0.7982 

0.8069 
0.8023 
0.7977 

0.8065 
0.8018 
0.7973 

0.8060 
0.8014 
0.7968 

0.8055 
0.8009 
0.7964 

0.8051 
0.8005 
0-7959 

46 

% 

0.7955 
0.7910 
0.7865 

0.7950 
0.7905 
0.7861 

0.7946 
0.7901 
0.7856 

0.7941 
0.7896 
0.7852 

0.7937 
0.7892 
0.7848 

0.7832 
0.7887 
0.7843 

0.7928 
0.7883 
0.7839 

0.7923 

0.7878 
0.7834 

0.7919 
0.7874 
0.7830 

0.7914 
0.7870 
0.7826 

49 
50 
51 

0.7821 
0.7778 
0.7735 

0.7817 
0.7773 
0.7731 

0.7812 
0.7769 
0.7726 

0.7808 
0.7765 
0.7722 

0.7804 
0.7761 
0.7718 

0.7799 
0.7756 
0.7713 

0-7795 
0.7752 
0.7709 

0.7791 
0.7748 
0.7705 

0.7786 
0-7743 
0.7701 

0.7782 
0-7739 
0.7697 

52 
53 
54 

0.7692 
0.7650 
0.7609 

0.7688 
0.7646 
0-7605 

0.7684 
0.7642 
0.7600 

0.7680 

0.7638 
0.7596 

0.7675 
0.7634 
0.7592 

0.7671 
0.7629 
0.7588 

0.7667 
0.7625 
0.7584 

0.7663 
0.7621 
0.7580 

0.7659 
0.7617 
0.7576 

0.7654 
0.7613 
0.7572 

57 

0.7568 
0.7527 
0.7487 

0.7563 
0.7523 
0.7483 

0-7559 
0.7519 
0.7479 

0-7555 
0.7515 
0-7475 

0.7551 
0.7511 
0.7471 

0-7547 
0.7507 
0.7467 

0-7543 
0.7503 
0.7463 

0-7539 
0.7500 

0-7459 

0-7535 
0-7495 
0-7455 

o.753i 
0.7491 
0-7451 

58 
59 
60 

0-7447 
0.7407 
0.7368 

0-7443 
0.7403 
0.7365 

0-7439 
0.7400 
0.7361 

0-7435 
0.7396 
0.7357 

0.7431 
0.7392 

0-7353 

0.7427 
0.7388 
0-7349 

0.7423 
0.7384 

0.7345 

0.7419 
0.7380 
o.734i 

0.7415 
0.7376 
0.7338 

0.7411 
0.7372 
0.7334 

61 
62 
63 

0.7330 
0.7292 
0.7254 

0.7326 
0.7288 
0.7250 

0.7322 

0.7284 
0.7246 

0.7318 
0.7280 
0.7243 

0.7315 
0.7277 
0.7239 

0.7311 
0.7273 
0.7235 

0.7307 
0.7269 
0.7231 

0.7303 
0.7265 
0.7228 

0.7209 
0.7261 
0.7224 

0.7295 
0.7258 
0.7220 

64 
65 
66 

0.7216 
0.7179 
0.7143 

0.7213 
0.7176 
0.7139 

0.7209 
0.7172 
0.7136 

0.7205 
0.7168 
0.7132 

0.7202 
0.7165 
0.7128 

0.7198 
0.7161 
0.7125 

0.7194 
o.7i57 
0.7121 

0.7191 
0.7154 
0.7117 

0.7187 
0.7150 
0.7114 

0.7183 
0.7147 
0.7110 

67 
68 
69 

0.7107 
0.7071 
0.7035 

0.7103 
0.7067 
0.7032 

0.7099 
0.7064 
0.7028 

0.7096 
0.7060 
0.7025 

0.7092 
0.7056 
0.7021 

0.7089 
0.7053 
0.7018 

0.7085 
0.7049 
0.7014 

0.7081 
0.7046 
0.7011 

0.7078 
0.7042 
0.7007 

0.7074 

0.7039 
0.7004 

70 
7i 
72 

0.7000 
0.6965 
0.6931 

0.6997 
0.6962 
0.6927 

0.6995 
0.6958 
0.6924 

0.6990 
0.6955 
0.6920 

0.6986 
0.6951 
0.6917 

0.6983 
0.6948 
0.6914 

0.6979 
0.6944 
0.6910 

0.6976 
0.6941 
0.6907 

0.6972 
0.6938 
0.6903 

0.6969 
0.6934 
0.6900 

73 
74 
75 

0.6897 
0.6863 
0.6829 

0.6893 
0.6859 
0.6826 

0.6890 
0.6856 
0.6823 

0.6886 
0.6853 
0.6819 

0.6883 
0.6849 
0.6816 

0.6880 
0.6846 
0.6813 

06876 
0.6843 
0.6809 

0.6873 
0.6839 
0.6806 

0.6869 
0.6836 
0.6803 

0.6866 
0.6833 
0.6799 

76 
77 
78 

0.6796 
0.6763 
0.6731 

0.6793 
0.6760 
0.6728 

0.6790 
0.6757 
0.6724 

0.6786 
0.6753 
0.6721 

0.6783 
0.6750 
0.6718 

0.6780 
0.6747 
o  6715 

0.6776 
0.6744 
0.6711 

0.6773 
0.6740 
0.6708 

0.6770 
0.6737 
0.6705 

0.6767 
0.6734 
0.6702 

79 
80 

0.6699 
0.6667 

0.6695 

0.6692 

0.6689 

0.6686 

0.6683 

0.6679 

0.6676 

0.6673 

0.6670 

CONVERSION  TABLE  FOR  CONVERTING  BaSO4  TO  SULPHUR. 


Mgs.  of 
BaSO4 

Milligrams  of  Sulphur 

0.0 

O.I 

O.2 

o.3 

0.4 

0-5 

0.6 

0.7 

08 

0.9 

p 

i 

2 

o.oo 
0.14 
0.28 

O.OI 

0.15 
.29 

0.02 
0.17 
0.30 

0.03 
0.18 
0.32 

0.04 
0.19 
0.33 

0.06 

0.21 
0.34 

0.08 

0.22 
0.36 

O.OIO 

0.23 

0-37 

O.OI  I 

0.25 

0.39 

0.012 
0.26 
0.40 

3 
4 
5 

0.41 
0-55 
0.68 

•43 
.56 
.70 

0.44 
0.58 
0.72 

0-45 
0-59 
0-73 

0.47 
0.60 
0.74 

0.48 
0.62 
0.76 

0.49 
0.63 
o.77 

0.51 
0.65 
0.78 

0.52 
0.66 
0.80 

0-53 
0.67 

0.81 

6 

7 
8 

0.82 
0.96 

1.  10 

.84 
.98 
.11 

0.85 
0.99 
•  13 

0.86 

1.  00 

•  14 

0.88 
1.  02 
1.16 

0.89 
1.03 
1.  17 

0.91 
1.04 
1.18 

O.Q2 
1.  06 
1.20 

0-93 
1.07 

1.  21 

o-95 
1.09 
•23 

9 

10 

it 

1.24 

1-37 
I-51 

•25 
•39 
•53 

.27 
.40 
•54 

.28 
•42 
•55 

1.29 
1-43 
1-57 

I-3I 
1.44 
1.58 

1.32 
1.46 
1-59 

1-33 
1-47 
1.61 

1-35 
1.49 
1.62 

•36 
•50 
.64 

12 

13 
14 

1.65 
1.79 
1.92 

.66 
.80 
1.94 

.68 
.81 
1-95 

•69 

•83 
1.97 

1.70 
1.84 
1.08 

1.72 

1.86 
1.99 

1-73 
1.87 

2.01 

1-75 
1.88 

2.02 

1.76 
1.90 
2.03 

•77 
•9i 
2.05 

15 
17 

2.06 

2.20 

2.34 

2.08 

2.21 
2-35 

2.09 
2.23 

2-37 

2.10 
2.24 

2.38 

2.12 
2.26 

2-39 

2.13 
2.27 

2.41 

2.15 
2.28 
2.42 

2.l6 
2-30 

2.44 

2.17 
2.31 
2-45 

2.19 
2.32 
2.46 

18 
19 

20 

2.48 
2.61 

2.75 

2.49 
2.63 

2.77 

2.51 
2.64 

2.78 

2.52 

2.66 
2-79 

2.53 
2.67 
2.81 

IS 

2.82 

2.56 
2.70 
2.84 

2.57 
2.71 

2.85 

2-59 
2-73 
2.86 

2.60 
2-74 
2.88 

21 
22 
23 

2.89 
3.03 

3.16 

2.90 
3-04 
3-i8 

2.92 
3-06 
3J9 

2-93 
3-07 

3-21 

2.95 

3.08 

3.22 

2.96 
3-10 
3-23 

2-97 

3-ii 
-  3-25 

2.99 
3.12 
3.26 

3.00 
3-14 

3-27 

3-oi 
3-15 
3-29 

24 

II 

3-30 

3-44 

3-58 

3-12 

3.45 

3-59 

3-33 
3-47 
3-6i 

3-34 
3.48 
3-62 

3.36 

3-49 
3-63 

3-37 
3-51 
3.65 

3-39 

m 

3.40 

3-54 
3.67 

3-41 
3-55 
3-69 

3-43 
3.56 
3-70 

3 

29 

3-71 
3.85 
3-99 

3-73 
3-87 
4.00 

3-74 
3-88 
4.02 

3.76 
3.89 
4-03 

3-77 
3.9i 
4-05 

3-78 
3-92 
4.06 

3-80 
3-94 
4.07 

3-8i 
3-95 
4.09 

3-82 
3.96 
4.10 

3-84 
3.98 
4.11 

30 
3i 
32 

4.13 
4.26 
4-40 

'    4-14 
4.28 
4.41 

4-15 
4.29 

4-43 

4-17 
4-30 

4-44 

4.18 
4-32 
4.46 

4.19 
4-33 
4-47 

4.21 

4.22 
4-36 
4-50 

4.24 
4-37 
4-51 

4-25 
4-39 
4-52 

33 
34 
35 

4-54 
4.68 
4.81 

4.83 

4-57 
4.70 
4.84 

4.58 
4.72 
4.86 

4-59 
4-73 
4.87 

4.61 
4-75 
4.88 

4.62 
4.76 
4.90 

4-63 
4-77 
4-91 

4-65 
4-79 
4-92 

4.66 
4.80 
4-94 

36 

y 

4-95 
5-09 
5-23 

4-97 
5-10 
5-24 

4.98 
5-12 
5-26 

4-99 
5-13 

5-27 

5-01 
5-15 
5.28 

5-02 

5.16 

5.30 

5-03 
5-17 
5-31 

5-05 
5-19 

5-33 

5-06 

5-20 

5-34 

5.08 

5-22 

5-35 

39 
40 
4i 

5-37 
5-50 
5-64 

5.38 

£S 

5-39 
5-53 
567 

5-41 

1! 

5-42 
5-56 
5-70 

5-44 
5-57 
5-71 

5-45 
559 
5-72 

5-46 
5-60 

5-74 

5.48 
5.61 
5-75 

5-49 
5.63 

5-77 

42 
43 
44 

5-78 
5-92 
6.05 

5-79 
5-93 
6.07 

5-8i 
5-94 
6.08 

5-82 
5.96 
6.09 

5-83 
5-97 
6.11 

5.85 
5.98 

6.12 

5-86 
6.00 
6.14 

5-87 
6.01 
6.15 

5-89 
6.03 
6.16 

5-90 
6.04 
6.18 

9 

47 

6.19 
6.33 
6.47 

6.20 

6.34 
6.48 

6.22 

6.36 
6.49 

6.23 
6.37 
6.51 

6.26 
6.38 
6.52 

6.26 
6.40 
6.53 

6.27 
6.41 
6.55 

6.29 
6.42 
6.56 

6.30 
6.44 
6.58 

6.31 
6.45 
6-59 

48 
49 
50 

6.60 

6.74 
6.88 

6.62 
6.75 
6.89 

6.63 
6.77- 
6.90 

6.64 
6.78 
6.92 

6.66 
6.80 
6-93 

6.67 
6.81 
6.94 

6.69 
6.82 
6.96 

6.70 
6.84 
6.97 

6.71 
6.85 
6.99 

6.73 
6.86 
7.00 

5i 
52 

53 

7.01 

7-15 
7.29 

7-03 
7.16 
7.30 

7.04 
7.18 
7-3i 

7-05 
7.19 
7.33 

7.07 
7.20 

7-34 

y.o8 
7.22 
7.36 

7.10 
7-23 

7-37 

7.11 
7-25 

7.38 

7.12 
7.26 
7.40 

7.14 
7.27 
7-41 

54 

n 

g 

7-44 
7.58 
7.71 

7.45 
7-59 

7-73 

7-47 
7.60 

7.74 

7.48 
7.62 
7.76 

7-49 
7.63 
7-77 

7-51 

m 

7.8o 

7-54 
7.67 
7.81 

j'te 

il 

59 

8.12 

7.85 
7-99 
8.13 

7.87 
8.01 
8.14 

7.88 

8.02 

8.15 

7.89 
8.03 
8.17 

7.91 

8.05 
8.19 

7.92 
8.06 

8.20 

7-94 
8.08 

8.21 

7-95 
8.09 
8.23 

7.96 
8.10 

8.24 

60 
61 
62 

8.26 
8.39 
8-53 

8.27- 
8.41 
8.55 

8.28 
8.42 
8.56 

8.30 

8.43 
8.57 

8.31 
8.45 
8-59 

8.32 

8.46 
8.60 

8.34 
8.48 
8.61 

8-35 
8.49 
8.63 

8-37 
8,50 
8.64 

8.38 
8.51 
8.66 

8 

65 

8.67 
8.81 
S.QS 

8.68 
8.82 
8.96 

8.70 
8.84 
8-97 

8.71 
8.85 
8.99 

8.73 
8.86 

Q.OO 

8.74 
8.88 
9.02 

8.75 
8.89 
9-03 

8.77 
8.90 
9.04 

8.78 
8.92 
9.06 

8.79 

8-93 
9.07 

66 

67 
68 

9.09 
9.22 
9.36 

9.10 
9.24 
9.38 

9.11 
9-25 
9-39 

9-13 
9.27 
9.40 

9.14 
9.28 
9.42 

9-15 
9.29 
9-43 

9.17 
9-31 
9-45 

9.18 
9-32 
9.46 

9.20 
9-33 
9  47 

9.21 
9-35 
9-49 

69 
70 
7i 

72 

9-50 
9-63 
9-77 

9.91 

9-52 
9.64 
9.78 
9.92 

9-53 
9.66 
9.80 

9-93 

9-54 
9.67 
9.81 
9-95 

9-57 
9.68 
9-82 
9.96 

9-57 
9.70 
9-84 

9.98 

9-59 
9.71 
9.85 
9-99 

6.60 
9-73   • 
9.86 

10.00 

9.61 

9-74 
9.88 

10.02 

9.62 

9-75 
9.89 
10.03 

344 


CURVE  FDR  CALCULATING  LJLL  AEE5  OF 

CYLINDRICAL  TANK5  WITH  CURVED  HEADS 

IN  HDRIZDNTALFD5ITIDN. 


ft 
h 
ls< 

s 

U 

3 

it  2t 


»/j 

o 
n 

z 


25  JO 


•4-0  AJ 


345 


INTERNATIONAL  ATOMIC  WEIGHTS. 

Revision  of  1915 
As  Published  by  the  American  Chemical  Society. 


Name  of  element 

Symbol 

Atomic 
Weight 

Name  of  element 

Symbol 

Atomic 
Weight 

Al 

Sb 
A 
As 
Ba 
Bi 
B 
Br 
Cd 
Cs 
Ca 
C 
Ce 
Cl 
Cr 
Co 
Cb 
Cu 

& 

Eu 
F 
Gd 
Ga 
Ge 
Gl 
Au 
He 
Ho 
H 
In 
I 
Ir 
Fe 
Kr 
La 
Pb 
Li 
Lu 
Mg 
Mn 
Hg 
Mo 

27.1 
IO2.2 
39.88 
74.96 

137-37 
208.0 
II.O 
79.92 
112.40 
40.07 
I32.8I 
12.  OO 
14025 
3546 
52.0 

58.97 

93-5 
63.57 
162.5 
167.7 
152.0 
19.0 

157.3 
69.9 

72.5 
9.i 
197.2 

3-99 
163.5 
i.  008 
114.8 
126.92 

I93-1 
55.84 
82.92 
139.0 
207.10 
6.94 
174.0 
24.32 
54-93 

200.6 

96.0 

Nd 

Ne 
Ni 

Nt 
N 
Os 
O 
Pd 
P 
Pt 
K 
Pr 
Ra 
Rh 
Rb 
Ru 
Sa 
Sc 
Se 
Si 
Ag 
Na 
Sr 
S 
Ta 
Te 
Tb 
Tl 
Th 
Tm 
Sn 
Ti. 
W 
U 
V 
Xe 

Yb 
Yt 
Zn 
Zr 

144-3 
20.  2 
58.68 

222.4 
14.01 
I90.9 

16.00 
106.7 
31.04 
195-2 
39-  10 
140.6 
226.4 
102.9 

8545  . 
101.7 
150.4 
44.1 
79.2 
28.3 
107.88 
23.00 

87.63 
32.07 
181.5 
127.5 
159-2 
204.0 

2324 
168.5 
119.0 
48.1 
184.0 
238.5 
51-0 
130.2 

172.0 
89.0 

65.37 
90.6 

Nickel  • 

Niton  (Radium 

Praseodymium  .... 

Rhodium  

Pnhalt 

Ruthenium  

Scandium  

Silver  • 

Sulfur  

Pnlrl 

Tellurium  

Terbium    

Thallium  

Thulium  

Tin 

Lanthanum  

T  pad 

Ytterbium  (Neoyt- 
terbium  

Yttrium 

Zinc 

INDEX. 


A 

ACID  PAGE 

in  oils  230 

in  tar  199-205 

carbonic,  in  air 243 

carbonic,  in  boiler  scale 240 

carbonic,  in  gas 120 

AIR 

composition  of  volume  and  weight 341 

determination  of  carbon  monoxide  in  (see  Gas  Analysis) 
determination  of  carbon  dioxide  in 243 

ALKALIES 

in  ash    224 

in  cement   272 

in  fire-clay 224 

in  water   215 

alkalinity  of  boiler  water 214 

ALUMINUM 

in  boiler  water 214 

in  bolier  scale 214 

in  fire-brick  223 

in  fire-clay  223 

AMMONIA 

in  concentrated  liquor 133 

in  gas    167 

in  weak  liquor 133 

in  waste  liquor 133 

AMMONIUM  SULPHATE 

analysis  of   152 

impurities  in   153 

free  acid  in 152 

ASBESTOS 

analysis  of  (see  Refractories) 

ASH 

general  analysis 42 

determination  of,  in  coke  and  coal 17-30 

ATOMIC  WEIGHTS 

table  of  345 

B 
BABBITT  METAL 

analysis  of  238 


347 


BAUME  HYDROMETER  TABLE 

correspondence  with  specific  gravity  .......................  342 

correction  table  ...........................................  236 

BEARING  METAL 

analysis  of   ...............................................  238 

BENZENE 

in  gas    ....................................................     79 

in  tar   ....................................................   197 

in  drip  oil  .................................................   186 

analysis  of  commercial  product  ............................    180 

BENZOL  (see  Benzene) 

BOILER 

scale,  analysis  of  ........................................  '  .  .  213 

water,  analysis  of  .........................................  213 

BOILING  POINT 

determination  of  ..........................................     53 

BROMINE  NUMBER 

determination  of    .........................................     44 

BRONZE   (see  Bearing  Metal) 

C 

CALCIUM  OXIDE 

in  lime   ...................................................  239 

CALORIFIC  VALUE 

determination  of,  in  coal  ...................................     30 

determination  of,  in  coke  ..................................     30 

determination  of,  in  gas  ...................................    112 

determination  of,  in  oil  ....................................     30 

determination  of,  in  tar  (see  Oil) 

CARBON 

determination  of,  in  steel  ..................................  273 

fixed,  determination  of,  in  coal  and  coke  ...................     17 

free,  determination  of,  in  tar  ..............................    197 

total,  determination  of,  in  iron  and  steel  ....................  273 

CARBONATES 

determination  of,  in  boiler  scale  (see  Lime) 

determination  of,  in  lime  ..................................  240 

determination  of,  in  water  (see  Water  Analysis) 

CARBONIC  ACID  (see  Carbon  Dioxide) 

CARBON  DIOXIDE 

in  air   ....................................................   243 

in   furnace   gases  ..........................................    120 

in  illuminating  gas  ........................................     84 

CARBON  DISULPHIDE 

in  gas   ....................................................   1  78 


348 

CEMENT  PAGE 

general 243 

analysis  of  270 

testing  of  244 

CHIMNEY  GASES  (see  Fuel  Gases) 

CHLORINE 

determination  of,  in  water 214 

CHROMIUM 

determination  of,  in  steel 297-306-321-324 

Cl,AY    (FlRE) 

analysis  of  221 

CO2  (see  Carbon  Dioxide) 

COAL 

analysis  of 3 

determination  of  nitrogen 28 

determination  of  oxygen 29 

elementary  or  ultimate  analysis 24 

heating  value,  determination  of 30 

proximate  analysis  of 12 

determination  of  sulphur 18 

COKE 

analysis  of  (see  Coal) 

shatter  test  37 

COLD  TEST  OE  OILS 237 

COMBUSTIBLE  GASES 

heating  value 112 

CONGEALING  TEST  (see  Cold  Test) 

CONVERSION  TABLE 

metric  to  English 335-336-337 

chemical    328-329 

COPPER 

determination  of,  in  alloys 238 

in  steel    294 

CYANOGEN 

in  coal  gas 177 

in  spent  oxide 156 

in  cyanide  mud 156 

D 
DEAD  Oil, 

analysis  of  (see  Tar  products) 


349 

DISTILLATION  PAGE 

method   for  creosote  oil 200 

method  for  drip  oil 186 

method  for  gas  oil 46 

method   for  tar 193 

DRIP      Oily 

analysis  of   186 

DEW  POINT  OF  GAS 

determination  of    126 

E 
ENGLER  VISCOSIMETER 

description  and  use 233 

ETHYLENE 

determination  of,  in  gaseous  mixtures 86 

ETHANE 

determination  of,  in  gaseous  mixtures 86 

F 
FATS  AND  FATTY  ACIDS  IN  LUBRICATING  OIL 

determination  of    230 

FERRIC  OXIDE 

analysis  of  new 59 

analysis  of  spent 65 

FIRE  SAND  (see  Fire-Clay ) 

FIXED  AMMONIA 

determination  of 145 

FIXED  CARBON 

determination  of,  in  coal  and  coke 17 

FLASH  AND  FIRE  TESTS  OF  OILS 

methods  of  determination,  gas  oil 48 

lubricating  oil   233 

FLUE  GASES  (see  Furnace  Gases) 

FOULING  TEST  FOR  PURIFYING  OXIDE 

method    63 

FUEL  OIL 

analysis  of   42 

heating  value   of 30 

FURNACE  GASES 

analysis  of   120 

23 


350 


GAS  PAGE 

general  properties  table 339 

analysis  of  coal  and  water  gas  by  U.  G.  I.  modification  of 

Hempel's  apparatus    71 

Elliot  apparatus   89 

Morehead   apparatus    96 

analysis  of  flue  gas 120 

cyanogen  in  gas 177 

ammonia  in  gas 167 

hydrogen  sulphide,  determination  of 160 

sulphur,  total  determination  of  by  Referee  test  apparatus...  169 

calorimeter,  Junkers 112 

factors    334 

naphthalene  in  173 

carbon  disulphide 1 78 

GASES  AND  VAPORS 

table  of  constants 339 

GAS  Oil, 

analysis  of 42 

heating  value   52 

H 

HARDNESS  OF  WATER 

determination    213 

HEATING  VALUE  OF  COAL 

determination  in  calorimeter 30 

determination  of  gas 112 

determination   of   oil 30 

HYDROGEN 

determination  of,  in  coal  and  coke 24 

determination  of,  in  gases 88-123 

HYDROGEN  SULPHIDE 

determination  of,  in  gas 160 

HYGROMETER 

use  of 126 

I 

IRON 

oxide,  analysis  of 59 

oxide  (sponge) ,  analysis  of 59 

IRON  CARBONYL 

determination  of,  in  gas 179 


K 

KJEU)AHI/S  METHOD  PAGE 

for  the  determination  of  nitrogen 28 

L 
LEAD 

in  bearing   metal 239 

in  bronze  and  brass 239 

in  Babbitt  metal ' .  238 

in  solder 238 

LIGHT  On, 

analysis  of    199 

LIME 

determination  of,  in  boiler  scale   (see  Water  Analysis) 

determination  of,  in  boiler  water 215 

analysis  of    240 

LUBRICATING  OILS 

analysis  of 228 

M 
MAGNESIA 

in  lime    243 

in  cement   272 

in  refractories 224 

in  water 215 

MANGANESE 

in  iron  and  steel 281-302 

MARSH  GAS 

determination  of    86 

METHANE  (see  Marsh  Gas) 

METRIC  SYSTEM 

tables  of  English  equivalents 335~33O-337 

MIDDLE  OILS 

analysis  of  (see  Tar  Oils) 

MOISTURE 

in  coal  and  coke 12 

in  oxides 60 

MOLECULAR  WEIGHT 

determination  of   53 


352 

N 

NAPHTHALENE  PAGE 

in  gas 173 

in  tar   186-199 

melting  point  of 211 

NICKEL 

in  steel 295-300 

NITROGEN 

in  coal  and  coke 28 

O 

OILS 

creosote    200 

gas    42 

lubricating    228 

tar 199 

OLIFIANT  GAS  (see  Ethylene) 

OXIDE  FOR  GAS  PURIFICATION 

analysis  of   59 

fouling  test   63 

OXYGEN 

in  flue  gas 123-124 

in  illuminating  gas 85 

in  coal   24 

P 
PAINT 

analysis  of   217 

PHENOL 

in  tar  199 

PHOSPHORUS 

in  iron  and  steel 284-312 

in  coal  and  coke 24 

PIGMENTS 

analysis  of,  in  paint 217 

R 
REFEREE  TEST 

description  of  method  and  apparatus 169 

REFRACTIVE  INDEX 

determination  in  oils 52 

REFRACTORIES 

analysis  of   221 


353 

S 

SAMPLING  PAGE 

coal  and  coke 4-8 

gas 71 

oxide    65 

tar    130 

SILICA 

in  iron  and  steel 292 

in  refractories    222 

in  water  214 

SOLDER 

analysis  of   237 

SOLIDS,  TOTAL 

in  water    213 

SPECIFIC  GRAVITY 

of  coke   38 

of  gases in 

of  oils   56-137-205 

STEEL 

analysis  of   273 

SULPHATES 

in  water    215 

in  boiler  scale  (see  Water  Analysis) 

SULPHUR 

in  coal  and  coke 18 

in  oil 57 

in  gas 169 

in  iron  and  steel 288 

free,  in  spent  oxide 67 

total,  in  spent  oxide 66 

SULPHURETED  HYDROGEN 

in  gas   160 

T 
TABLES 

atomic  weights 345 

calculating   water   analysis 328 

conversion  of  barium  sulphate  to  sulphur 343 

conversion  of  English  to  metric 335~33^-337 

conversion  of  specific  gravity  to  Baume 342 

conversion  of  elements  to  compounds 329 

curve  for  calculating  ullages  of  tanks 344 


354 


TAR  PAGE 

analysis  of   130 

acids    200 

free  carbon  in 197 

in  spent  oxide 67 

water  in    132-190 

TIN 

in  bearing  metal 239 

in  bronze 239 

in  solder   237 

TITANIUM 

in  fire-brick   225 

V 
VANADIUM 

in  steel  - 317-325 

W 
WATER 

boiler,  analysis  of 213 

estimation  of,  in  tar 132-190 

Z 

ZINC 

determination  of,  in  brass 239 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


Off:    j-r   « 

DO^ 

'  •    1 

wo 

DEC   tOT33£ 

MAY  18  19- 

8 

t 

aOAug'eovr 

„    .wD  -^ 

H»-  -w 
r   C       ^ 

stvs  » 

epi'lT  ON  \l  L 

JAN  1  *t  1938 

U.  C.  BERKELEY 

LD  21-100m-8,'34 

UNIVERSITY  OF  CALIFORNIA  LIBRARY 


